I just installed two TV wall mounts in my TT. I got mine from Walmart.com, model Ematic EMW3301, for $17.98 each. Will handle most TV from 13" to 37". It has all the different size screws for the mount on the TV since they vary by screen size. I wanted a mount that you can remove the TV when you travel since TT's do not have a soft ride. The TV just lifts off of the mount for that and I lay them face down on the bed for transport. As was mentioned, don't trust the backer board to be where the "TV Mount" sticker is located. I suggest you find the smallest drill bit you can get your hands on and drill a pilot hole to find the backer board, that way if you miss it you won't have a big hole to cover up. The sticker was right at the top edge of the backer board in both cases, bedroom and living area. Don't use a long lag screw that comes with the mount because they were 2 1/2" long and the walls are 1 3/4" thick. I used a lag screw that was threaded all to way to the head, not over 1 1/4" max. A 1" would probably be just as good. Most LED TVs will not have a lot of weight, maybe 10-12#. I have a 17" in the bedroom that weighs about 6# and the 29" in the living area is about 10#. I think the backer board is probably 1/2" plywood and not over 3/4".
2014 Palomino Puma 25RS
2011 F-150 Super Crew XLT
Days camped in 2014 - 23
Camped 2015 - 47
Camped 2016 - 51 done - 6 more planned so far