My lamp monitor says brake lamp out, and intermittently(sometimes as fast as 5 seconds on and off, sometimes it stays on for a few hours) it says tail lamp out.
This is not my car; picture grabbed off internet to show example. The half that is circled in red is always on when the lights are on...the other side only comes on when I hit the brakes, I believe, but now that I'm getting intermediate tail lamp, maybe it doesn't anymore. Will check this afternoon. Taking off the rear assembly and holding all bulbs in my hand, all of them light up how they should. I believe that a wire attaching into the socket is bent up/shorting out intermediately.