It probably depends on the city, but I've heard that since Firemen work in long shifts living at the station a good deal of them also run contracting businesses

It probably depends on the city, but I've heard that since Firemen work in long shifts living at the station a good deal of them also run contracting businesses on their days off from the station. It was explained to me that this was usually construction, but I imagine there are more than a few Fireman-coders out there.