Put a screw in the hole with one of those plastic screw head covers that you canbuy at Home Depot or Lowes. I used those when I mounted a shelf on a single ply wall.
Thanks for all the suggestions! I think I figured it out. I contacted the manufacturer that bought the factory where my trailer was built, Outdoors RV. They are selling me some seam tape for my wallpaper pattern. It should work perfect to cover these little holes.