I've caught a lot of mice with my earlier version of this trap, designed for Adam's peanut butter jars. (We eat a lot of peanut butter.) I've even caught two mice at the same time. This version is designed for standard 32oz (or standard 1 liter) wide-mouth mason jars. It consists of a weighted ramp that tilts down to let the mouse into the jar, but when it tilts back up, it blocks the exit and has no features for the mouse to grab onto to open it back up. Just smear a little bit of peanut butter on the inside of the jar to bait it, screw the lid on, and place the trap along a wall where your mice might be travelling.

Make sure to check your traps often, and don't place them where the sun might bake some poor trapped mouse. Once you've caught your mouse, take it a ways away (think kilometers - they have excellent homing skills), unscrew the lid and tilt him out to his new home.

Printing
I printed this in PLA (Prusament Pearl Mouse, of course) with 0.2mm layers with no supports. It's easy to print and the exact settings aren't critical.

Assembly
The ramp has a slot in the side so that it can be weighted with 3 pennies, or similarly sized washers (about 7.5g). Hold them in place with a drop of superglue. The ramp pivots using two short lengths (about 15mm long) of 1.75mm dia. filament. Just push the lengths of filament through the holes in either side of the entrance chamber and into the sides of the ramp. The holes in the sides of the ramp are tapered so the pins hold with a friction fit.