how do you get rid of mice in a stored motor home over the winter.?

place sticky boards where they are running...maybe in middle of floor place some crunchy peanut butter on a paper plate for a day or two to attract them, then place numerous snap traps baited with the peanut butter or sticky traps near the plate. Don't think I would use baits in this situation. If the trailer is parked in a yard make sure any tall grass or debris is removed

When I stored mine for the winter, I used a product called Vi-con (made by De-con). Not for areas where pets or kids are present as there is no antidote. In the Spring, I would find many dead mice within 3 feet of the product.

put out some rat/mouse poison, they eat it, in 2-3 days they dead

nope, see the link