Well, that stupid mouse had been making noise in the same wall since I wrote the OP. Doing some interneting, it was suggested that if you hear the scratching continually in the same place, and especially during the day vs night, the mouse has probably trapped himself in the wall and will die there.
I heard no scratching last night or this morning, and coincidentally just popped the hatch to the crawlspace and saw a mouse in the trap that I set there yesterday. So maybe that's the mouse, or it might be another one. It flipped the trap and I'm only seeing it from the bottom, but it looks like a light colored mouse with a white tail. Unlike the mice I catch in the garage and shop. I despise my crawlspace, so won't be going down to reset the trap until before my evening shower, but I'll be curious to see what kind of mouse this is right side up.