Ed, Point Lookout SP in MD is always looking for good hosts. They will take you from April - November or any period of time over a two week period. There are 6 campgrounds within the park and at least one host to each campground. Two hosts in a few of the campgrounds is really needed, but they usually don't have that many volunteers.
They require 20 hours per week per camping unit, so if there are two of you, that's 10 hours a week. If there are 4 of you, that's only 5 hours per week. They only require you to be there on Friday evening, Saturday and Sunday until about 7:30 or 8:00, so you may be able to work and still host if that would float your boat.
PM me if you would be interested. The rangers there are great and you are appreciated for what you do.