MURPHY55347 wrote:
Buy a flat cold air return grill. They make them in many different sizes. They may only come in white but you could always paint it a color to blend in with the wall.
Yes, I owned a camper that had a grill like that mounted to the outside of the camper. It looked like a normal intake for something (Fan, fridge, etc.) I couldn't figure out why something like that was in that location. I removed it and found that the previous owner had poked a hole in the side of the camper. After filling the hole it still looked bad so he just covered it up with this.
No one ever suspected a thing or noticed it at all.