About your mouse problem… our old farmhouse had a mouse problem too. The little turds got into everything, and it is most annoying. I can sympathize. Really.
We don’t have a mouse problem now.
Step 1. Plug up and/or stopper the holes. Any crack that is 1/4″ wide, they can fit through, so plug that up too.
Step 2. Traps. Lots of traps. We prefer the old fashioned Victor traps. You don’t need the huge tactical nuke model. That just makes a mess. Trust me. The small ones will be fine. Mice love, love, love peanut butter. We use Jiff Extra Chunky. Place your traps along walls, behind and between appliances, under desks, etc. Even in ventilation ducts. Check them every day.
Step 3. Barn cats. We had 3. Now we’re down to 2 (one died of old age). Even if you don’t like cats, get them. If you feed them once a day – in the morning – they’re fine and will stick around for the free eats. But they get hungry at night and night is when mice are active. Since establishing these protocols, we have not seen a mouse – or even signs of mice, like poo or holes chewed in stuff – in almost 3 years despite having a full larder downstairs, a full pantry upstairs and all sorts of crap that mice like…
The wicked flee when none pursueth..." - Proverbs 28:1