As others have said, there are differences between AC and DC rated switches, and often switches are not DC rated and won't hold up as well for a DC load.
As a practical matter, you'll probably have no problems with using (decent) household light switches for RV lights. I would not hesitate to do so; the consequences of a failing light switch are pretty benign--a light that won't turn on or won't turn off, which is not a safety hazard or anything like that. If there is physically enough space for the switches, go for it.
Dimmer switches won't work, of course, nor will fancy smart switches or other things that are electronic rather than mechanical in their action.
