One of my Korean friends from college said that objects in her apartment were constantly moving and being rearranged. Like, she could leave a coffee cup on the kitchen counter, go to the bathroom, and when she returned, it was suddenly on her kitchen table. I doubt she had short-term memory problems.
My mom has an old friend, who's also an atheist, but she was "visited" every night by something that walked around her room, and sat at the foot of her bed. She lives alone and it wasn't an intruder because my parents helped her to check, and make sure that all of her doors and locks were secure.
I'm not saying that any of these could be attributed to demonic entities or ghosts, but I certainly wouldn't negate it, either. There's too much about this world that we don't fully understand.
