Yeah... around here shelters separate out 'barn cats' from 'pet cats', barn cats are tolerant of people but not really socialized to appreciate people. Rather than taking an existing pet cat and putting him or her to work, I'd try adopting a barn cat and putting them to work. Often, barn cats do retire and become pet cats towards the end of their life, if circumstances allow.

Of course, cats can cause a different sort of trouble than mice. :D

I'm dying at the idea of a maintenance cat. In my mind he's wearing little overalls and carrying a wrench.