Brake lights?

Just about ready to get my 71 coupe a P.A. inspection and was chacking all the lights, they all work except the drivers side brake light. The passenger side brake light works. I can't fiqure this out. No power to the driver side, but power to the passenger side, and the power comes in on the drivers side. Do you think it could be the switch up at the brake pedal? Do they go bad often? That's the only thing I can think of.

Thanks Dean.