Adding 12 volt power plug to camper is a good thing. You can run these straight to the battery so you know you have a good strong connection. This is one of my favorite brands from Orelly's
What is good about it comes with a lock washer to lock behind what ever you drilled into. It come with plenty of wire to run to the battery.
I put two in my camper. The first was in hole where the Thermostat went for the heater. Since, i wasn't going to use the heater this was a good place back by the back bed. I use a CPAP machine and this will be very handy for using it back there on 12 volt power.
The next spot i put it was in the front buck area because it was so close to the battery it was a short run of cord.
Finally this is something i picked up at the Dollar tree for $1.00
It is a light switch LED light. I mounted it there because the camper is dark at night before i can reach for a 12 volt light.