This is pretty much Exactly What It Says On The Tin. The characters go into a room or house that is disturbingly clean and orderly. It's not that the room is nearly empty and clean, like with Ascetic Aesthetic (it probably has a lot of interesting bric-a-brac), but that it's all methodically organized and meticulously, surgically clean. Even a neat-freak will be freaked out, because the place will look like a cross between a pharaoh's tomb and cleaning commercial... that is to say, a place sealed for ages but still as pristine as they day it was made.

Typically, the owner is a Stepford Smiler of some sort, a Serial Killer, or an army veteran who's snapped to the point they methodically repeat actions and routines. Or all of the above. If this is the case, then there's probably a Room Full Of Crazy where the owner "dumps" all their chaotic tendencies. The rest of the house being so disturbingly perfect may be an expression of their need to seem normal, or to try and hide their dark secrets.

• In season 1 of Heroes, Sylar's apartment is so clean and neat, it looks like he was trying to seem normal. Of course, there's a Room Full Of Crazy hidden in it.
• In Falling Down, Kirk Douglas' character William Foster has his room in his mother's house this way.
• Practical Magic has a spell that "cleansed" a hotel room of every psychic impression it had as a means to throw off anyone snooping in. A side effect was that the room looked as though the maid's had used hazmat suits and rulers to make it utterly, perfectly pristine. The Empath who went to read the room was suitably freaked out.