Steve, Welcome to the forum. As for the two lights on each side of the license plate, they are probaby back up lights. The previous owner may have installed a switch to turn them on and off since really, they aren't bright enough to use for backing a trailer that big. Look around and see if maybe there's a switch tucked up under the license plate or around that area. Hopefully, you'll find one. If not, they may have been wired to act as lights to illuminate the license plate. They should not be on if the RV is not connected to the tow vehicle.
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS