Mice enter homes in search of food, water and shelter and usually set up camp behind walls. If not killed and removed in a timely manner, mice can destroy your home by chewing through electrical wires, contaminating your food and by leaving trails of feces and urine throughout your home. Learning how to kill a mouse in the wall is essential if you want to live in a clean, rodent-free environment.
Locate the pest's entrance and exit holes in the wall. According to the University of California Statewide Integrated Pest Management Program, mice can squeeze through openings slightly larger than 1/4 inch across.
Place snap traps near all wall entrance and exit holes and along wall corners. Mice regularly leave the comfort and safety of walls in search of food and water. To prevent tearing or cutting into your wall, set snap traps near wall openings and in places where you've witnessed recent mice activity. You can purchase snap traps at hardware stores.
Check the traps regularly, primarily at dusk. According to the University of Missouri Extension, mice are occasionally seen during daylight hours, but they are most active at night.
Remove the dead mouse and snap trap to prevent odor. Put on a pair of latex gloves and carefully place the mouse carcass, along with the trap, into a secure garbage can.
Use caulk or steel mesh wire to close all cracks and holes in your walls to prevent mice from re-entering walls. You can purchase caulking or steel mesh wire at hardware stores.