Not sure if you're joking, but volunteer work is quite different than having to stand at the checkout line packing backs in a commercial setting.

Volunteer work is a lot like part time work, in that it's mostly low skill, and the work varies from physical labor to office work, and from behind-the-scenes jobs where you only interact with other volunteers to intensely face-to-face jobs where there's no hiding from the emotions of the people you serve.