This is true with automatic transmissions. If you have a manual transmission however, there is a plunger switch located near shifter linkages (depends on which of 4 manual transmissions you have)

Any problem with lights I've had on 1 bumpside and 2 dentsides (and I've had them), have been solved by checking and sometimes replacing the bulb sockets. Any wiring issues I've had have been within 2" of the bulb. I have a test light that is a sharp probe to stab into insulation, that has a bulb and a ground wire. One bad bulb socket can cause seemingly strange symptoms with the lights and the dash indicators. I've always found replacement bulb sockets for little money at local auto parts stores. Check that you have power near the bulb socket, and that grounds are good.