I just purchased a 1994 ford four winds RV

SOURCE: 1998 wrangler turn signal/brake light short

your socket may not be grounded properly, I have seen this before, and the simplest way to fix is change the socket with a new one.Not another used one it may also be bad.

SOURCE: 1993 jeep grand cherokee limited no running lights/tail lights.

Id look at the headlight switch and do some voltage tests to see whats coming out of there. Pay close attention to any wires which look like someone was in there already.People can mess stuff up faster and better than the vehicle can by itself!

SOURCE: 94 Mazda B3000

Check the brake light switch located under the dash, and is energized by depressing the brake pedal.

SOURCE: left rear turn signal and brake light dont work

You have a broken wire to the turn/brake light portion of the light as they use the same wire. Or where the plug goes into the light assy could be bad. Torsion mount lights are horrible and you should think about replacing with a universal light that you can wire direct.

SOURCE: Chevy Cavalier--Socket Burning Back Right Blinker?

it sounds like you are getting corrosion in the socket from water leaking in. Then you end up with high resistance which then causes more current draw whcih then overheats the socket and bulb.
You need to clean the socket very good or replace it if it's on a short wireing harness with a connector. They are @ $20.00.
Then you need to spray some electrical contact cleaner/deoxidizer in the socket to kep it protected. Go to Radio Shack or an auto store to get this.
Finally, look for how the water is getting in there. Sometimes the lens has a gap between the outer lens and lamp body. Seal the entire joint where the lens is attached to the body with a clear silicone sealer. Let us know your outcome. Good luck.