That depends on the job. There are plenty of volunteer positions with lots of accountability. I've done a number of volunteer roles that involve life safety - you can bet your butt you're accountable in those.Volunteer work is easy, because there is no accountability. If you do the job great, you get a pat on the back. If you hose it up entirely, then you come back the next day for the chance to hose it up again.
Thinking back to the volunteer roles I've done over the past few years, almost all of them have needed some sort of licence or certification.