Fire alarms, security systems, and other such means of alert are intended to be passive ways of letting people know that something's gone wrong, and are meant to signal that a specific kind of hazard is present. However, sometimes a character is in a bad spot and needs help, but has no active means to summon anyone. By deliberately tripping whatever alarm is available, they can broadcast their distress and (hopefully) count on whoever shows up to assist them.
Note that an alarm being tripped for its intended purpose, as a means of demonstration of function, or as a distraction for enemies doesn't count.
- In Red Rackham's Treasure, Tintin is exploring underwater in Calculus's submarine for the wreck of the Unicorn when its propeller becomes caught in a group of weeds. Unable to extricate himself, Tintin deploys the only effective means of communication the submarine was equipped with: a smoke canister intended to be used to mark the location of the shipwreck. This succeeds at attracting his friends' attention, and they use an anchor to pull the submarine out.
- An Italian story from the Mickey Mouse Comic Universe has Mickey and Goofy locked inside a freezer by some thieves. Freezing and unable to unlock the door, Mickey uses lit matches to set off the freezer's fire alarm, alerting a nearby police officer and leading to their rescue.
- In The Abyss, after Lindsey finds out that the Navy SEALs have brought a nuclear warhead onto the rig, she goes to their room and demands that they remove it. When one of them threatens to have her forcibly removed and has another SEAL grab her, Bud triggers an alarm. This brings the rest of the rig's crew to the room on the double and causes the SEALs to let Lindsey go.
- In Aliens, when Ripley realizes that she and Newt are locked in the facility's medical bay with live facehuggers, she first tries to get the attention of the Colonial Marines in the control room through one of the security cameras, not knowing that Burke has turned off the camera feed. After failing to break a window with a chair, she gets the idea to use her cigarette lighter to trip the fire suppression system. The Marines don't know what's actually happening, but Hicks sees the alarm notification on the computer and they come to her and Newt's rescue.
- In Die Hard, John is desperate to get help to fight the terrorists who have taken over the Nakatomi building, and triggers a fire alarm in order to get firefighters (and hopefully police) to come and check it out. The terrorists respond by calling 911 and telling them that it's a false alarm.
- The fire alarm is used twice in this manner in John Carpenter's The Thing (1982):
- The Thing first infiltrates the camp in the form of a dog. After it is put in the kennel with the other dogs, it starts to transform so it can absorb and duplicate them. MacReady hears the real dogs' terrified barking and howling from several rooms away, and pulls the fire alarm to get the attention of the other members of the team so they will come and help out.
- Windows discovers that Bennings has been attacked and copied by the Thing, and tells MacReady and Fuchs. MacReady looks out a window and sees the Bennings-Thing running away. The fire alarm is pulled again to bring the other team members, but it isn't shown who did it.
- In Pirates of the Caribbean: The Curse of the Black Pearl, when Barbossa's crew is attacking the Dauntless after luring most of the Marines away, a British sailor manages to ring the ship's bell, alerting Norrington and the Marines to the attack.
- The Fisher King. While breaking into a Big Fancy House, the protagonist finds the owner has taken a drug overdose, and so deliberately triggers the burglar alarm on his way out.
- Exploited in Dreadnought!. Piper is confined to her quarters under computer guard after the initial meeting with Star Empire's hijackers, but knowing that the computer guard won't keep someone locked in a burning room, she sets off the fire alarm by overheating some circuitry in the wall with her curling iron. It works because (thanks to her engineer boyfriend) she knows how to disable the alarms that would normally alert the bridge and bring a whole pack of Red Shirts down on a prisoner under computer guard whose room actually suddenly caught fire.
- In Polar Star, Arkady Renko is locked in the freezer of a Soviet factory ship by some people trying to kill him. He tries to get out by lighting some oily rags near the heat sensors, but it doesn't work. Ironically he then gets freed by someone walking past who hears him singing (as he's now high from the fumes).
- In the Babylon 5 episode "Exogenesis". Marcus tries to contact security with Dr. Franklin's comlink. Since Marcus's DNA doesn't match Dr. Franklin's, it doesn't let him connect. However, it does trigger an Unauthorized User alarm and notifies security of his location, exactly what he was trying to achieve anyway.
- At the beginning of Deus Ex: Human Revolution, an environmental alarm goes off when Adam is talking to Sarif and he is sent to investigate. Adam discovers that mercenaries are assaulting the building. An e-mail you can read later reveals that Adam had set up the alarms so that an environmental alarm would go off if the security alarms were disabled.
- Exploited in Among Us. Hitting the Emergency button summons all the players to the room it's located in for a meeting. If a Crewmate sees an Impostor come out of a vent and/or kill, and can beat them to the button, calling the meeting will save them from being killed (at least until possibly the next round) and can potentially lead to the Impostor being gotten rid of.
- Subverted in one Grrl Power strip. Sydney panics when she sees Sandy start behaving very strangely, and is a hairsbreadth away from pulling the fire alarm when Sandy has an explosive sneeze.
- In an episode of Fireman Sam, Norman and a woman see a fox and think it's a wolf, so they ring the fire alarm to get help.
- In the Dexter's Laboratory episode "Trapped with a Vengeance", when Jonny the Janitor traps Dexter in a class room using barred gates on every possible opening, Dexter pulls the fire alarm. It works, but only enough for Dexter to escape into the vents before Jonny turns up the heating system.
- In an episode of Star Wars: The Clone Wars, General Grievous sends elite droids to take over an outpost facility. Being outnumbered, the remaining troopers decide the best way to contact help is to destroy the entire base for a relay signal to be sent to the Jedi.