Tail light stays on

Thanks for the replies.
Dana67 - I just purchased the car and I'm trying to troubleshoot problems. Ihaven't done anything to the car yet.
67Dart273 - I pull the bulb to keep the battery from draining.

More info - If I turn the headlights on, the left tail light (the one that stays on) goes out. Turn off the headlights and it comes back on. Same with the blinker, turn on the left blinker and the light turns off and it blinks as it should. Turn off the blinker and the light stays on. Thanks for the help.

This is a classic ground issue symptom.