I grew up in an old home -- it was one of the first built on my road when it was just a pasture overlooking the ocean.
Sadly, even though it was built in the 1800s, I've never managed to find a hidden passageway or secret room. I'm not sure I'd have the guts to go explore it even if I did find one, but that's a whole other issue.
Unlike me, though, when Redditor JiveBomber found this creepy room in their mom's house, they explored and came to one chilling conclusion.
This looks like a normal built-in shelving unit, right?
Well, after some inspection, they discovered that it was anything but typical. JiveBomber found this space behind it...
In the room, there was this hole in the wall.