Have you heard of the bucket technique? Its where you have a bucket that has a stick that rolls so that's where you slather the peanut butter. When the mouse tries to get on the roller, they will lose their footing and drop into the bottom of the bucket - which you can fill with water for maximum efficiency.
Something like this is fine so you could even make this a DIY project for the week. I got this picture from this site: http://gentlemanhomestead.com/diy-five-gallon-bucket-mouse-trap/ and their situation seems to mirror yours, hope this helps!
"which you can fill with water for maximum efficiency"
I wouldn't fill it with water. Just keep them alive and release them in a forest or something, 5 km+.
This is cool! I think my friend @fabrews also mentioned this trap. It looks easy to make. Considering I did not catch anything this morning I'll think about it.