Switch is bad. pull it out and look for a part number, stuff like that is not unique to RVs it will be from some major manufacturer (GM, Ford ect.) once you know what it came from you can get it from a parts store.
I needed a hvac control assembly for an old Bounder last week it was from a 90-93 Dodge Caravan.
If you can't find one post a picture, I love to "hunt" on the internet.
If it is an odd switch try a search like this and scroll till you see something that looks like your switch. https://www.google.com/search?q=univ...hPBiQQ_AUIBygC