I had experienced two of these.
The first one (which I don't really recall, because it happened when I'm still 2 years old) happened when my aunt bought a weird-looking statue from a sacred place and put it on my house for a few days. I accidentally touched the statue, and guess what? I got possessed. i couldn't eat or drink anything for a few days. Luckily, the spirit that possessed me was a good one, so she (yes, she!) released me under certain conditions, which was some good prayings (Buddhists show know these kind of exorcism).
The second one happened just a few weeks ago. I was in my room with my sister, and the lights were turned off. I was laying in my bed in a position where I can see the window, and my sister laid on the opposite direction. We chatted for a while when a strange silhoutte of a woman walked past the window. I felt scared afterwards, but didn't dare to tell my sister; she would call me a chicken. I talked to my mother about this the day after, and she said that maybe it was a silhoutte of someone on the street, projected on the curtain. But there were two eerie things that keeps bothering my mind. The first one: the silhoutte walked awesomely fast as it was floating, and motionlessly while we humans walk in motion. The second, the window is high, so an average human would only reach the middle of the window. Instead, the silhoutte nearly reached the top of the window.
I never saw that silhoutte again, and I wish not to see it again. I think it's a
succubus, but wtf. I never know.
Jam it back in, in the dark.