Ah yes, the raining inside symptoms! 3 yrs ago we were camping with our Trailmanor over on Lopez Island (San Juan Islands, WA) and we had about 6 days of rain in 10 days of camping. Plus it was a chilly September weather. We had to wipe down the walls several times a day. Openning the roof vents and cracking windows didn't help, just too humid! The TM had aluminum walls inside, so were a bit 'cooler' and more readily condensed, but still!
Now in the FF, last year camping in OR, again cool September weather, but not a lot of rain, we again had condensation. Not as bad as the TM, but still had to wipe the windows and upper corners of walls. Opening the Fantastic Fan and cracking a window helped a good deal. But remember, with every breath to expel, you are sending out humidity into a closed vessel, and the same goes for every cup of coffee or tea, or can of soup. If the temps are cool, condensation occurs .. and/or if you are in an area with high humidity, it is just multiplied. If you are in an area where these conditions are persistent, and you are on shore power, a small dehumidifier might be a good idea and would help. If this is more of an occasional situation, just be aware that you should be ready to wipe and air out on your trip. Then air out the rig when y0ou get home. My best suggestion.
As far as mold goes, we store our TT under an ADCO cover and put 3 moisture absorbing 'buckets' in it (with the little pellets in them). We've never had any moisture issues from the 'interior rain' events!
