Finding where they are coming in might help. We have an RV that our daughter stays in when she is here.
We have used moth balls in the past. Since our daughter doesn't like the smell, I have looked for other repellents.
I read that lavender and rosemary will repel them. These are the ones I have growing in the garden. I have not tried them.
You might try planting these in or around your home to keep the mice away: any type of mint, amaryllis, sweet pea, lavender, daffodils, wood hyacinth (or squill), grape hyacinth, alliums, catnip, camphor plant, elderberry, euphorbias, and wormwood. Oak and bay leaves are also known to repel rodents.
https://www.flowershopnetwork.com/blog/plants-repel-mice/
One organic farmer’s wife, Kari Warberg Block, knew there had to be a better way than traditional poisons and traps to keep her farm and home mouse-free. Researching natural ways to repel mice without chemicals and traps, she soon discovered a combination of plant oils that create an aroma rodents can’t stand.
Soaking plant fiber in this blend of essential oils carried the scent in an easy-to-use way. She created a product that would ward off mice effectively in barns, homes, sheds, RVs, trailers, and just about any other enclosed space.
That product is Fresh Cab. Now farmers across the nation are using the rodent deterrent to keep their farms infestation-free, without killing any mice or exposing their family and animals to potential dangers.
What Is Fresh Cab?
Fresh Cab is an EPA-registered plant-based rodent repellent that works by emitting an odor that keeps mice and rats away. To use it, you simply place a pouch of the product in the area where you want to fight rodents. It does all of the work for you.
https://www.earthkind.com/knowledge-base/pest-library/repel-mice-little-known-farmer-wifes-secret/