[rab] The only way I find works well is those wooden snappy traps baited with bread and cheddar cheese rolled into a small ball. Poison may work but although I've found it eaten, I've never found a dead mouse to confirm. Alternatively try this.
[Boolbar] Pshaw. What are they talking about? Intelligent children like me did play it properly. About four times. We even knew the rule that if (A) triggered (O) directly, the mouse automatically escaped!
[rab] If you haven't already disposed of the beastie. Do you wish to kill the thing or catch it alive and release it somewhere other than your kitchen rather than zap the poor wee thing and have it die a lingering death with a broken back or neck? If so, I have used a wonderful device which works rather well. It's a commercial trap, quite cheap, which is formed from a square section of tubing, one end sealed the other with a spring loaded door. It is also bent. Bait (in my case a dob of peanut butter!) down the sealed end. Place on floor/shelf/whatever with door latched open beneath the device. Mouse wanders in and heads for the other end. Weight of mouse combined with gravity causes the 'far end' to rock back to level - it's the bent end which is elevated. Front end then rises - obviously - and allows the door to snap shut. Viola! one contained mouse. All that remains is to release the thing in an enviroment of your choosing.