I have a real fear of mice. I know it is irrational but I do. Homemade mousetraps can be very easy to put together and they don't need to kill the critters. You need a very large plastic bucket and you need to construct some dodgy steps leading up to the bucket. Smear something like peanut butter inside the rim to act as bait. The mice will tumble into the bucket and you can let them free. Make sure that you take them at least a quarter of amile away from your home.
You don't want them back so make sure you cut off all food supplies. Clean behind cookers and down settees and armchairs. Think about planting mint in and around the home. Mice hate mint.Or soak peppermint oil in cotton and place them around the home.