[was skruske]

It looks like a serrated lock washer. It's small, like for a #8 or #10 machine screw. Might from some electronics or maybe for radio, TV or computer case.

TinMan is on the right track. Perhaps it is from a light fixture, lamp or ceiling fan.

I suggest all available Varmints Den members converge on Indy so we can get to the bottom of this mystery.

Let's make it a pot luck.