If I have a felony expunged can I be a firefighter?

O.k im slowly but surely working my way through all my lifes dreams. Tried the navy, got denied, wanted to be a police officer, got denied. I didnt think 3 years ago a stupid 19 year old kid could get in trouble for a freaken FIGHT. thats it a fight and have this thing follow me around for ever. So my felony is expunged can I be a firefighter?