Hello. I think there is an internal circuit difference between 12v
LEDs and 115v LEDs. I don't think you can screw on in a 115v socket and power it with 12v. You might be able to change the bulb socket to a 12v bayonet socket and then redeploy the wire as a 12v wire. Actually you may not need a socket at all as LEDs will last longer than the camper. Just hard wire the LED array. I'd ask the RV LED or one of the other internet suppliers.
If your trailer is like an Airstream, you may have a converter in it somewhere. Airstream went to all 12v devices sometime in the mid sixties. They called it univolt.
So I think you're going to need to do some electrical planning to convert your old camper to all 12v, solar charged, and maybe a converter to charge batteries on 115v too. Maybe you need a 12v water pump, a 12v ceiling vent fan, and a 12v furnace fan?