As Roy B indicated, use a back-board and then screw the mount to the backboard.
In my previous camper, this was an interior wall. The other side was the bathroom. I used Liquid Nails and a bazillion fine finishing nails with an air gun to mount the board. I did not go through the wall. There were only a couple spots where I hit an actual stud. We removed the television when in transit, thus the reason for the flat mount with the easy lift-off hooks:
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My current trailer had a specific spot for the television mount. We took this one off when we sold the trailer and I put it in the bedroom of our Outback which had a designated place for it. We still remove the television from mount when traveling. Lay it on the bed. No problem. We can take it outside that way too.