When I was very young, we lived in a house that had the usual "ghost" activity–hearing footsteps, hushed voices in the next room, etc. But the really cool thing was the basement door. It would open on its own, I'm not talking open an inch or two when you closed another door nearby, I mean it would swing fully open like someone was walking through it. My parents tried locking the door and it would still swing open on its own.
By the time I was learning to walk, my dad was concerned I would fall down the steps, so he went down into the basement and just said, to no one in particular, that he had a young daughter upstairs and could they please be careful with the door. Ever since then, the basement door would open, and then slowly shut on its own. – Anonymous