I volunteer for a small local group, and they've now asked us to agree to help out for a set number of hours in a local playgroup, for which I think they get paid (but we, the volunteers, don't, just expenses like our parking costs). I don't mind doing it, but it feels a bit more like I'm an employee, and while I don't want minimum wage etc, I wouldn't want my local group to run into trouble.
Am I right to be concerned?