I am a churchwarden, which is a volunteer role with statutory responsibilities.
My church has a large staff team (paid and unpaid, but churchwardens don't make it onto our website, even though we are the first people that welcome visitors and regulars to our church).
We obviously run on volunteer labour, eg flower-arrangers, but they have a particular job to do and would not be asked to do anything outside of their lane.
Churchwardens, on the other hand, are expected to mop up everything.
My policy is to do my statutory duties, the things that interest me, but never to cover for someone who is paid to do their job.
Comments from others about paperwork and interviewing - this is called Safer Recruitment and it is particularly important when working with vulnerable groups and children.
Safer Recruitment requires there to be a job description, references, interview, DBS (if appropriate), training and appraisal. If you really think about it, it is reasonable, although tedious.
I get a break from CW this week, as I am a volunteer SATs invigilator at my DIL's school.