What connector is this behind the radio?

I'm installing a factory radio into my Buick to bring back the stock look of the inside. While doing so I found this lose gray wire with round connector. Does anybody know what it is for? I didn't see a spot for it on the radio. Thanks.

 

Light bulb socket?

 

Looks like the ashtray light socket. The holder is probably still in your car.

 

Never even considered that, and that's what it is. Thanks guys.

 

Throw a bulb in it, it should work.

 

Careful of the bulbs you use, some are too hot and will melt plastic around it. 68-69 lights over the ash tray area are known for this.