Do you really mean tail light (parking light) such as is on the 1st gen trunk lid? Or do you actually mean one of the brake lights or even a turn signal light? Alternately, do you mean the center brake light?Rear tail light socket is overheating (burnt)???
Was there any green corrosion in the socket or on the base of the bulb? That would be a sign of water getting in there somehow.rear Tail light(brake/clearance) socket;installed new socket 3 years ago & it has got hot enough it is discolored again? how can this overheating be corrected???