The "humane" traps work just fine. In particular, the larger cage style ones have the nice side effect of using the first few mice caught, as live bait for luring more of them.

Lee Valley Tools sells EDIT: used-to sell /EDIT one trap with a wind-up spring loaded "door", for batting them into the cage quickly. Other stores sell similar things. I have used a totally passive trap (no windup) that worked well with peanut butter as bait.

But the mice will keep on coming back (or new ones will move in) so long as (1) there is a way for them to enter the building, and (2) there's a good reason for them to enter the building (food, shelter).

Cheers