Like many have said before it really depends on the location and what is expected.
If it is 24-hours/week of cleaning, mowing, and maintained the park in order to have a free place to park...it better be a nice CG with amenities that are worth my time.
Additionally, I would want to know when I am needed. If for instance it was 3x days @ 4-hours per day and then had the rest of the week off (for a couple - 24 hours) then maybe -- if the park offered enough amenities and was in the right location.
I would not volunteer our time in a location that wouldn't provide enough time to enjoy the area. I have seen many a position advertised for 30-40+ hours a week for a CG that charges $500-600/month and then have a strict schedule that equates to WORKING.
When I retire it is to enjoy the fruits of my labor, not to labor for someone else.