Mounting TV

Thank you, I am going to use Mich's advise and try to remove the covering to be sure where mount should be placed.

Or use a density type stud finder.

Could you mount it from the bottom, if the base of the cutout is sturdy enough?

My Itasca is pre-wired for a TV in the bedroom. My opposing wall is the shower also. I pulled the panel off the wall, where the connections are located and they put wood backing plates in the wall, where the mount should be installed.
Your MH most likely has something similar. You can feel around for signs of backing plates, or try to remove whatever is covering the area where your TV should be mounted, for a better idea of where the mount should go.

I just took a pic of mine, but I'm having issues loading it. You get the idea anyway. ;)