Ok, I installed the new tail/brake light and everything works normal now!! YEAH!!
I posted two pics of the old tail light/brake light. the 4 screws you see on the back loosens the circuit board for the lights, BUT you cannot remove it out of the casing. Its a sealed system to keep moisture out & there is no way to get to the circuit board/lights unless you cut out the lens. The 4 screws has little gaskets on the screw heads which were dry rotted and falling apart. So moisture must have got to the circuit board.