This morning as I approached the bathroom of my apartment, I saw the light in the bathroom turn off. The door of the bathroom was open. I waited for someone to exit. No one did. I walked into the bathroom, and saw it was empty. Of course, there's a completely natural reason why this might happen: the bulb burning out. But I flicked the light on and off; there was no problem with the bulb.
Regarding the same bathroom, I twice observed the toilet flushing by itself on October 21, 2017. The second time was particularly odd. I had just returned to my apartment, and just when I first saw the bathroom, the toilet flushed. I waited for someone to leave the bathroom, but no one did. It was empty. I observed the same thing on Halloween of 2016: the toilet flushing by itself one time early in the day and one time in the evening. These days (October 21, 2017 and October 31, 2016) were the only days the toilet flushed by itself. If you Google for "ghost flushing," you will hear people say that if you have a toilet with a failing flapper, ghost flushing may occur. But the type of toilet I have does not have a flapper.
The light turning off by itself was the inverse of what I observed on January 6, 2016: a light turning on by itself. The light, directly plugged into the wall socket, was a very sturdy and reliable lamp that requires a firm click of a switch to turn on. I have had no difficulties with this lamp or this socket since that date. This year I have also seen eight cases of the flashlight at the back of a Samsung tablet turning on by itself, all while the tablet was turned off and leaning against a wall. I have also seen 15 cases of an electric toothbrush turning on by itself.
Perhaps all such incidents are similar to bright or colorful orbs appearing in photos -- maybe they're all just cases of some mysterious external reality giving us a kind of a "shout out," a kind of "hello, we are here" signal.