Welcome to the forum. Unfortunately, I doubt that high humidity is enough to make your interior wall bow. If it is, run a dehumidifier in the unit and reduce the humidity. Or you could run your a/c units which will also dehumidify the air. You did not state what RV you have or how old it is.
Happy Camping, Safe travels and may our paths cross someday!
40' 2000 Monaco Windsor, ISC350 Cummings w/Allison 3000 6 speed and Jeep Cherokee toad. We're all old but, we keep on trucking!