What's causing them to back out? Are they stripped? If they are backing out, maybe try Loctite. If they're actually stripped, SuperGlue or similar adhesive may work for holes that already exist. Many on this forum recommend Command Strips rather than putting new holes in their camper walls.
Try taking 1 or 2 of the smallest size nylon tie wraps and bend into "L" shape and insert into the hole before you put in the screw, they won't disintegrate. Clip off the tails once you seat the screw Beyond that its "molly time"
If they're not stripped and are just backing out, some clear (or your favorite color) fingernail polish will help keep them from backing out. Locktite is a good idea, but clear nail polish is much cheaper and comes in smaller quantities.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!