Sorry you are having issues! A lot of older structures in JC have these issues.

As a short term solution, you can do the following...a bit of work, but worked for me.

Sprinkle spices around where they are likely to get in. I use pepper, crushed red pepper flakes, garlic...especially garlic powder. Mice tend to stay away from pungent spices.

Also there is a youtube video that you can use that plays a high pitched sound that repels mice, roaches (anything with acute hearing or antennae. This works when you are just sitting around and want peace without seeing them scamper by.

High Pitch Sound For Mice