Tail light stays on

Thanks Trailbeast. It may sound like a classic ground issue but when I ground it with a wire, the bulb gets brighter (like going from tail lights to brake lights). The green wire going to the socket is powered 100% of the time, thats why it's on all the time. I disconnected the harness at the driver kick panel and the green wire is powered going back under the dash. I'm guessing it is contacting a hot wire under the dash somewhere. Does this sound reasonable?

Yep, sounds reasonable to me.
And we also know there is a ground issue at that socket.
The light shouldn't change at all when you ground the socket.
Unplug your headlight switch connector and see if the light goes out, and if it does the problem is likely in the headlight switch. hint (which always has power)