I had mice last year when I stored my coach along the fence line of the facility that bordered a vacant lot that was overgrown.
First, moved the coach to an open area away from any fence.
Second, got me a few traps, put that peanut butter and jelly spread on the BOTTOM of the trap trigger.
I had all of them buggers in short order. Works every time without fail.
Finally, took me two weeks to completely clean out the coach and toss everything them buggers peed and pooped on.
Traps, peanut butter/jelly