What regular job would be closest to what Dean and Sam Winchester do?

I know the obvious ghost chaser type stuff. But I mean more like are they closer to cops/detectives/Feds or are they closer to military Special Forces/CIA (since they do pretend to be FEDs most but CIA and SF do that kind of underhanded means too in order to slip in and out of places undetected and I keep imagining them with a military upbringing due to their dad). Thoughts?