1. Get a toilet paper tube and crease two lines to form a flat sided tunnel.
2. Put a treat on one end of the tube: A cracker and dab of peanut butter works great.
3. Get a tall (at least 20 inches) bucket. A trash can works well.
4. Balance the tube precariously on the edge of a table or counter with the treat hanging directly over the tall sided receptacle.
5. The mouse will scurry to the treat (they like tunnels) and fall into the trap.
Set the fella loose at least a mile away from your abode.