Tail Lights Stay On

The tail lights on my 1993 Olds Bravada remain lit after the I get out..
Sometimes If i fiddle with the brake pedal they will go off, and sometimes If i slam the door they will go off...
They have come on without turning the vehicle on at all when I have opened one of the rear doors. Any idea what may be causing this or what I can do to fix it?

there is a white plastic switch assembly in the shape of a half moon that clips around the base of the steering column and controls the backup lights and the ignition switch shift interlock based on the position of the column shift lever. I kicked mine loose once and broke the retaining clips and got pulled over by a cop and was given a warning ticket. before i got around to fixing it the white backup filaments burned out, but the turn signals and brake lights continued to work. it's still broken, but i took it by the DMV and got the ticket voided on a visual inspection.