If I ever revealed my role pm, the town, not the mafia, would be greatly hindered in its efforts by it.

I am not a mafia role, and I'm not out to kill you all. I haven't even tried, and if I did, it would have to be with a vigilante group like anyone else. If I start killing people, it will probably be obvious enough that you'll realize it right away. Then you can kill me for it. Right now, I'm only working to help the town.