I think you have a roof leak. Water could be running down from an unexpected spot on the roofing system into the area where you are observing it.

This happened on my hunting trailer which started life as a construction office trailer (sor of looks like mobile home). Like you said, walls were wet and the ceiling/wall interface was wet. I solved it by installing a metal roof on top of the entire existing structure. I probed for rafters (which unhelpfully were unevenly spaced and not even the same spacing at the ridge and eve. So, you had to probe till you hit wood). I cut out the ridge vent length with a circular saw. I used 2x4's as the purling strip, then put metal over everything. It solved the moisture problem and ALSO made the temperature drop inside by a ton. I guess all that galvanized metal with a 1.5" air space separation was able to reject a bunch of heat. Only downside is cell signal went to zero and we had to install a booster.

EDIT: I don't know anything about how the two halves of a double wide are mechanically joined, but perhaps someone can chime in here on the possibility something has separated and allowing air flow into the center.

Last edited by M48scout; 08/09/26 04:41 PM.