Not the most interesting or thrilling story, but just kind of weird and unexplainable.
One time many many years ago, my older sister and I(f) visited some relatives in another city (NYC). It was maybe my second time in their apartment.
It was bed time, and my sister and I were sharing a bed. She went to turn off the light switch and walked back to the bed.
I could clearly see my sister walk back to the bed for a few seconds, as if the light were on. After 3 or 4 seconds, it went pitch dark and I could no longer see her or anything else.
The thick curtains were also drawn, to block out the city lights.
I asked my sister if the light did in fact turn off immediately after she switched it off. She said yes, obviously.
I asked her if she could still see clearly in the room after the light was turned off. She said no, it's dark.
I could clearly see her face, her movements while walking, where she was looking. All as if the light were on. I told her as much, that I could see her. She thought I was unsuccessfully trying to be funny or something.
It's never happened before and it's never happened again.
Just weird.