How about a garage?
I kniwwzhat he’s going thru. My garage got mice. As a result, they git into the dash board on my sports car. It was massively [relatively]to have the dash removed.
That’s a good idea, but squirrels have a way of squirrel-ing into the most impossible little spaces. There’s no way to keep them out - they are our Overlords.
(I bought one of those ‘squirrel-proof’ bird feeders. Squirrel found his way in, gorged himself, and was trapped in there. I took it down and let him out. No sense in killing him - you can pick them off all you want, but there are scores of reinforcements coming behind, just waiting for Their Own Chance.)