LOL.
Blob of peanut butter on a mousetrap in your attic. By morning, problem solved.
Those lil SOB's can sneak threw a 1/8 inch crack. He is just messing with you. If you do go the shotgun route don't for get to use ear plugs.
And post pictures!
Give him a cookie... and a glass of milk... and...
I put 3 more traps up in the attic brining the total to 9. There are also 3 bait boxes outside. Generally I keep 6 traps set and get 1-2 mice a year in the attic. With fields on 3 sides I was good with it, but never had one in the wall.
The mouse was still in the wall as of this afternoon, but has since gone quiet. So he either left peacefully (my 4 year old was playing his guitar and singing “Mouse, Mouse get out of ours house”) or burnt up all his energy and is going to die and leave a pungent odor.