I was messing with my window switch a while back but since then my car has been totaled and I never got around to figuring it out, I'm in the process of cleaning out and still don't know what this is, even after searching its part #...

Possibly a keyless entry antenna or something? came out of the drive door. It was not connected to anything.

 

I have one of these in my car, it is connected to a IR receiver mounted near the mirror.
I believe it has something to do with keyless entry.