Def harder than installing it in a house. That is unless your rv might have had a option for a fan already. As far as I have seen the wiring harness is the same for the model rv. So if it had an option for it the wiring might be there or really close by. Example is that I don't have a front tv, yet the coax and 110v wiring is there for a tv. Another example is I don't have a computer workstation/stand alone dinette, yet I have the electrical outlet tucked away in the sofa cabinet and it is just the right length for it to go where the workstation would be.
You can do 12v or 110v. Need to look at your ceiling and see if there are seams that have a trim piece in between (at least that's the way I was looking at doing it).
Figure out how to run the wiring then determine where there is framing in the ceiling to attach it.
Let us know what you decide. Pics are always great for others to see too
'16 Bounder 35K - 5 Star Tune, Roadmaster RSSA, TST-507 TPMS, Dish Network, Winegard RoadTrip, Wally, WifiRanger EliteAC
'16 Ford Focus - Blue Ox Avail towbar and baseplate - RViBrake2