use a live mouse trap. I use them to catch any stray mice that have escaped (though I typically can find them and catch them on my own and the only 'stray' mouse I caught in the mousetrap was actually a wild deer mouse LOL). But the live traps work well, especially wh en you know where the mouse is hiding. Just put the live trap as close as you can to where the mouse is hiding, come back in a couple hours to see if the mouse is in the trap. Or just leave it over night. Don't leave the mouse in it too long as they can die in the life traps if left in there long enough (overnight would be fine).