Found a lamp socket that is hot all the time..

[valk_ryder]

These two lamp sockets were hanging down like this when I bought the truck (72 fleetside). There's a hole on each end of the back side of the A/C control and it's pretty obvious that they are for the lamp sockets.

But one of the sockets is hot. Lights off, doors closed, and it is still hot. This can't be right, can it? The other socket only gets voltage when the instrument lights are on and it varies with the dimmer as I would expect.

It's the hot wire I'm wondering about.
Does the A/C control get 2 lamps, one on each end?
Is there any reason this one socket is hot all the time? If it had a lamp in it then the battery would run down.

The wire is gray and comes out of the factory harness.

thanks,
John