Many of the ghosts have a power related to who they were as a Living or how they died.
Thorfinn was struck by lightning and can now manipulate electricity to a small extent.
Alberta was a jazz singer and her humming can be heard by the Livings..
Isaac died of dysentery and he can create a sewage stench when a Living passes through him.
Flower the tripping hippie can make people high by passing through them, etc.
Trevor, no-pants finance bro, who has the power to interact with the physical world by concentrating really hard and pushing things with his finger. This seems odd, since it has nothing to do with him or how he died...until you realize that the womanizing, sex-obsessed Wall Street bro literally has the power to "finger" things.
Hetty's husband, Elias, known for his philandering, caused people to become uncontrollably horny. Had he not "gone down on them," he has vowed to disrupt every event at the B&B.
Sass's ghost power, the ability to enter and affect living people's dream, makes sense as well; dreams are a type of story in the mind and Sass can direct the way the story can flow.
Pete's ghost power is the ability to leave the mansion's grounds. This is foreshadowed by his frequent boasts about having been a travel agent in life, someone who manages the affairs of others looking to take trips, as well as the title of the episode it was revealed in, "The Traveling Agent".
The ghosts are unaffected by the sage and find it pleasant. It's supposed to ward off evil spirits and none of the ghosts is evil.
The way a majority of ghosts appear to date from fairly recent periods makes perfect sense, as there are simply a lot more people in recent times.
It's also likely that many ghosts just "get sucked off" or "go down" over time. Confirmed: Thorfinn had two other girlfirends who had been at the mansion before Flower.
The existence on Earth after death is a form of Purgatory for ghosts. If they have unfinished business, or need a chance to change for the better, once it happens they get sucked off. If, however, they declare that they will definitely not change any bad habits, they may get sent somewhere else, not so pleasant.
When we meet Jay's sister Bela, he and Sam say her name (pronounced "Bay-lah") several times, at least a few in Trevor's presence. So how did he not figure out what was going on before she showed up? Simple, he only ever saw it written, and probably assumed it was pronounced like Bella, with a *short* e!
When Sam and Jay get an Alexa, Alberta is the only one of the ghosts that it can hear. Given Alberta's ability to create humming audible to humans, it makes sense that she has some sort of vocal presence that can be picked up by technology.
Elias' Vault ghost-holding powers makes sense. The intention of a vault is to contain and imprison that which is within. It is meant to keep outsiders from entry to it. Where a house is designed to be open and welcoming, thus allowing the ghosts to enter by various walls and doors, the vault isn't. So any ghost trapped in it is bound by the intrinsic nature of vaults, and other ghosts are prevented from entering by the same nature.
Wouldn't this also be true about a locked door where you don't want unauthorized or uninvited people to enter, such as a bedroom? If so, would this also seal the entire room?
Thor's soft spot for children makes more sense after Season Two reveals one of the last things he did before traveling to the New World and subsequently dying was saying goodbye to his young son.
In "The Christmas Spirit", Thor can still see all the ghosts while possessing Sam. This may seem like a continuity error, since Hetty couldn't see any of them during her time possessing Jay, but there's a major difference. Hetty possessed Jay, but Thor possessed Sam.
Flower's old boyfriend giving her the personal nickname Daisy is because her legal name was Susan and a Black-eyed Susan is a type of Daisy.
Trevor seems to be getting better with manipulating real-world items since Sam and Jay moved in. Why? Since then, Trevor has had more practice with their keyboard-based electronic items; he still has issues with larger items, though.
In a subtle "Across the Pond" moment, US/Pete's arrow entered his neck from the right, while UK/Pat's arrow entered his neck from the left.
In "Ghostwriter," Jay is with Sam during Sass's story time, and appears to be listening to his story. It's really a kind of Translation Convention; Sam is relaying the story to Jay so he can also hear it.
In "The Heir," Sam gets $20,000 as an advance on her book about Isaac. Isaac convinces her to split the advance with him as collaborator. Try telling the IRS that Sam only has to pay taxes on $10,000!!
Thor and Bjorn being around over a thousand years after they died makes complete sense when you realize what culture they came from. The way for Norse warriors to get into Valhalla or Folkvangr, loosely compared to their versions of Heaven, was to die honorably in battle. Those who didn't went to Hel, a joyless, grim boring purgatory. Thor never got to die in battle and Bjorn likely didn't either considering he's got no battle wounds on him. Since they still firmly believe they missed out on their opportunity to enter the afterlife, they can't move on and be reunited with their loved ones. They're stuck in their own version of Hel and might remain on Earth for eternity since there's no way as ghosts to come to terms with their unfinished business of not dying in battle.
Hetty immediately accepting Isaac when he comes out to her seems rather out of left field for her character given her many outdated views, but it makes more sense when you consider that her own son Thomas was gay himself (Thomas murdered Alberta so that he could be with her husband, Earl). Even if Hetty most likely would not have initially accepted Thomas' sexual orientation, she would have had at least a century to come to terms with it and better understand him and by extension other gay people.
In "The Silent Partner," Trevor is able to take Isaac's $10,000 and turn it into a fortune, enough for Jay to finance the opening of the restaurant. Why didn't Trevor do this beforehand, since he knew Sam & Jay were needing money? After the Nigerian Prince scam, Sam specifically told him not touch her and Jay's finances again. Technically, T-money was using Isaac's funds, although Jay could have been held liable for when the stock nose-dived for a bit. Luckily, Sam & Jay (and Isaac) weren't greedy, and cashed-out, making the needed cash.
In "He Sees Dead People," Sasappis takes Hetty to the basement to show her the long forgotten painting of her with her bare ankle. Propped on the left side frame of the painting is a pair of small crutches, apparently made for a child.
Excluding the Cholera Ghosts, who wear medical patient gowns, not one of the ghosts we have seen has been in any kind of bedclothes. Every single one of them died awake.
This is debatable with Isaac, at least, who was probably unconscious or insensible on his deathbed given that he never knew his wife changed him into his uniform before he died.
Sam is lucky that the only ghost she saw at the hospital was of a doctor; chances are it also has some ghosts of patients who died there.
FB: Sam only came to the hospital to see a doctor, so the doctor's ghost was probably hanging around the exam/consultation rooms. Sam was talking to him, not realizing he was a ghost until the living doctor arrived late, and the ghost retreated into the filing cabinet behind the desk.
It must have been sad for the Cholera Ghosts to be stuck in a pesthouse alone and in the dark and then living under the basements as ghosts, forever having their lives ruined.
They seem to have adjusted, though, and it's implied that they don't think much of the 'above-ground' house, and aren't that interested in the ghosts that live there.
Its been mentioned with both Flower and Isaac that the physical state they died in carries over to their ghost self, even if in some cases in a lesser form. Dehydration from Cholera tends to make people light sensitive, so the basement could just genuinely be more comfortable for them.
It's best not to think too hard about the aftermath of Pete's death. All of those kids probably needed serious therapy after seeing their scout master die in front of them, especially the kid who accidentally shot him. Not to mention the repercussions the kid could face for it (she's a minor and it was an accident, but it's doubtful that the incident would be swept under the rug).
We do meet one of the kids, now all grown up, and she, at least, seems to have grown up well-adjusted (and even fondly remembers Pete and his first-aid lessons).
There's a good chance Sass's tribe must have encountered European colonists who either would have killed them through war or disease or a combination of the two. And Sass would have seen it all and be powerless to do anything since he's already dead.
Thorfinn died around the Early Middle Ages and until a) Sassapis and his tribe existed and b) Woodstone Manor were built and someone died there, he had no one to talk to. It's no wonder he's a little divorced from reality.
Even worse, his son Bjorn came looking for him, and died on land within shouting distance. Neither of them knew where the other was and they both were doomed to live alone until the Lanape tribe settled the land, centuries later.
Hetty's husband Elias would have been trapped under the Vault for decades with no one to talk to besides his corpse. Of course, he probably deserved it.
Isaac had sisters who all died before the age of two. A dark reminder that child mortality rates were high in his time.
If Sam visited the more dangerous neighborhoods in New York, there would be a good chance that Sam would see the ghosts of people that died of gang violence and crime.
This is confirmed when Jay wants to go to a particular coffee shop and Sam mentions that it's the former site of an execution site. She'd only know this if they had visited it once.
Confirmed again late in the second season when, after Jay reveals that he had applied for a job in New York, that Sam says that she can't go back to New York City as it's absolutely crowded with ghosts and that she had counted hundred in Central Park alone.
It would be horrifying if Sam visited the deep south, as she could see the ghosts of racists as well as the ghosts of slaves that suffered horrific deaths.
Stephanie died to a maniac with a chainsaw... but what about her boyfriend Tad, whom she was making out with in his car seconds before she got murdered? Either he was murdered too and went straight to the afterlife, became a ghost for a while before ascending to the afterlife before Sam and Jay moved into Woodstone Mansion... or he ran and left her to die instead to save his own skin.
Jessica the car ghost is still seen with the glass and blood in her forehead after her accident, which looks extremely horrifying.
Ghosts like Jessica who are bound to the vehicle means that any ghosts who are victims of ships going down, like the Titanic, might not be stuck on the surface of the ocean where they drowned but underwater as the body of the Titanic is stuck on the bottom of the ocean.
Worse, the Titanic is decomposing. What's going to happen to all the ghosts when the ship is gone? What happens to car ghosts when their car is turned to scrap and recycled?
Car ghosts can't walk more than five feet away from their cars. Cars don't last forever, so ghosts like Jessica eventually end up in junk yards where they're stuck in extremely small areas.
What happened to Molly's baby son after she died? She appears to have died young, and seems to be too underpaid to afford baby formula, so it is unknown if he died and went straight to the afterlife, became a ghost for a while before ascending to the afterlife before, or simply grew up as an orphan dealing with the horrid conditions of living in New York back then.
Isaac states to Benjamin Franklin that three of his five nephews survived the winter (implied to be the seasonal flu). A reminder that in the 18th century, people can die of various diseases (i.e. the seasonal flu) which are now treatable with vaccines and other medicines.
The modern ghosts (such as Flower, Trevor, & Pete) are lucky they died in The United States - There are Americans who aren't bilingual who are ghosts that died outside of America during America's many wars ( World War I , World War II , Vietnam War, etc.) in Europe or Asia. They have to be stuck in a place they are not familiar with and everybody around them is speaking another language include any other potential ghosts nearby.
Thorfinn and Sasappis likely were in this scenario at one point. Sure, Thor probably picked up some of the Lenape language over time, but given how poor his grasp on English, which he has been surrounded by for a longer period of time, is, it's likely that the only person the other could interact with for over 200 years couldn't properly communicate with them.
Elias’ has the ability to make anyone feel aroused when he walks through them. This by itself already falls into the realm of Double Standard: Rape, Sci-Fi. It is never stated whether or not the people he affects are capable of taking no for an answer. It is only the short duration that Elias’ powers last that keeps him from having the ability to turn people into rapists.
For someone like Sam, going to jail seems even more horrifying than it actually is, with prisoner ghosts who died from things such as the death penalty, being murdered by an inmate or beaten to death by prison guards, or dying from neglect in solitary confinement. Plus Sam could get into trouble if she mistakes prisoner ghosts with actual prisoners or said something out loud to a ghost which catches the attention of a prisoner...
It's implied that since some parts of the world there are more people dying than others (such as Asia and Africa) also means more ghosts who died horrific places. It's best if Sam does not visit Africa or Asia for vacation...
We finally learn the real way Hetty died, and boy does it fall under fridge horror the more you think about it. She strangled herself to death with a phone cord in order to insure her son would be able to inherit the family wealth before the cops could seize it. The way the room and the cord was set up makes it clear that Hetty would have had to actually strangle herself, nowhere to tie the cord to hang herself with it...this would not have been a quick way to go, and she would have had to keep forcing herself to keep the pressure up until the point of no return. The bloody cuts around the cord when she reveals it definitely do not show a pretty picture.
"The Travelling Agent" reveals that Pete's ghost power is not being bound by the ghost boundary. Given that the usual method of undoing ghostly possession is to put the possessed in the car and drive off the property, this might not work if Pete possesses someone.
