I have a demon story that I personally experienced. True story.
I was about 18 and I bought an electric typewriter. It was super fancy because it had a slot for a floppy disks, so it was almost like a computer! This was at the beginning of the PC revolution and they were still wildly expensive.
Anyway, I used it to type talks and stuff on it (and my original idea for a Star Trek book that I still think would have been awesome!) One night, when I was sound asleep, I was awakened by a loud clacking racket, like demons were throwing my TV around the room. I was too afraid even to open my eyes, because if I saw some red humanoid outline hovering over me, I don't know what I would have done. I don't even remember if I had the presence of mind to utter a coherent prayer. "Please, Jehovah, I'll stop making out with Sister Loose if you make this demon go away. Uh, in Jesus name. Amen." More likely I was just saying "Oh Jehovah, Oh Jehovah" over and over again.
So the demons left me alone pretty much by the time I was fully awake. The next morning I was surprisingly calm, I guess since the demons hadn't probed my nether regions or anything. I turned on my electric typewriter to work on my masterpiece, but when I flipped the switch, it turned it off. So I flipped it again to turn it on and it started this loud clacking racket as it centered the print head and all that stuff that modern printers do, except this was much louder.
The clock on my VCR (you kids don't know what those are... kind of like Blue Ray where you have to be very quick with the pause button if you want to catch the nip slip) was blinking. The power had gone out the night before, and when it came back on the typewriter started up.