I knew a guy who did very well with that niche. That was a few years ago, and I have lost touch with him. Regardless, the market is out there.
Understand, though, that mobile homes aren't really homes. They are considered vehicles for lack of a better term so you will have to develop some specialized knowledge to work that market.
That's actually good news because if you are the one who goes to that trouble, you can probably dominate your marketplace because you know something others don't.
You might even be able to parlay your knowledge into a course and teach it to others!