Release a mouse? They're going to be back to the house before you get there yourself.

Find a deep metal bucket with a sturdy bail. Take a can about the size of a tomato paste can and with your can opener remove both the top and the bottom of the can. (Better yet, if you can manage to remove the contents through a small hole, hammer a 1/2 inch or so diameter hole in the middle of each end of the can). Disconnect the bail and run the can over it. Re-attach the bail and position the can at the top of the arch of the bail that you have fastened somehow in a completely upright position (use duct tape, clothespins, clamps, whatever--this isn't pretty, but it works). Smear the can liberally with peanut butter. Fill the bucket 3/4 full of water. Find something like a paint stir stick (1 gallon size is fine) and prop it from the edge of a nearby piece of furniture or wood box, etc. to the bail next right next to the can with the peanut butter.

This has worked for backcountry rangers and lookouts since there were backcountry rangers and lookouts. They use this in the remote buildings where they have to live for short periods of time. The peanut butter can must move freely around the bail so that when mice step onto it it turns under their weight and drops them into the water.

Rule of thumb--ignore splashing when you are sleeping. But when the bucket gets so full of mice that the new ones can run over the tops of the dead ones and escape the bucket it's time to change the water. This happens when you hear the can turn but no splash following.

SRS