I’m not familiar with rural towns. I live in the suburbs and every town has a fire dept (which is why our parades are so long).
I know some fire fighters are voluntary because I always see signs requesting them.
I believe ours is a mix of both paid and voluntary because there is always some vote going on to raise taxes to expand the depts. or to add onto the fire dept. buildings.
Around here they’re all volunteer except for in the city. They do make a few bucks for going out on their calls and obviously the taxes pays for equipment.