Its not yet passive because i choose to spend most of my time on it to make it better, but i bought a cleaning business 10 months ago. I recently took a consulting contract for some additional money for expansion and it does run by itself (in the capable hands of my biz manager), however there are more optimisations i wish to make to it. Its the hardest thing i've ever done, but its at a stage where if i wanted to, i could simply take any time i wanted off and all i'd need to do is spend 15 mins a week entering payroll.
I've written about it before, if you want to look through my history.