A long time ago when I was in college, I got home late... Sometime around midnight, I went through my usual routine, brushed my teeth, washed up and went to bed. It was a full moon that night, so when I turned off the lights, a few seconds later the light from the moon slowly crept inside and dimly lit my room just enough to see my surroundings.
To my surprise, it started getting dark again. And for some reason, it seemed like there was black smoke emanating from the center of my room (about eye level while I was sitting on my bed). I couldn't understand what it was but it just kept on getting darker and darker until to my horror, I couldn't see the other half of my room anymore. It was completely filled with black smoke... It seemed as if it was an empty space of nothingness. The black smoke kept on occupying more space until it filled 3/4 of my room already and the only thing that wasn't filled with black smoke was my bed (where I was sitting).
Luckily, I'm used to seeing strange things and at the time this happened, I was in a bad mood and I didn't like what was happening. I simply yelled at whatever it was that I wasn't in the mood and to please stop bugging me. And to my surprise, the black smoke that filled 3/4 of my room started to disappear as if it was being sucked in by a vacuum at the center of my room (same spot where it came from). And after a few seconds the black smoke had completely disappeared and I could see my entire room again with the dim light from the full moon.
If anyone has any idea or has experience the same thing, your comments are very much welcome. Although I've seen so many things, it would be great to know what that black smoke was. Thanks.