A community or volunteer group can also be considered to be a social club. Depending on the organization of this group, it may need to be officially formed and may need its own EIN. A community or volunteer group that wants to have its own bank accounts, hire employees, and so forth, is going to need to be officially structured with an EIN. But a loosely formed unofficial group doesn’t require any such structure.
The determining factors are a bit of a gray area, but if the community or volunteer group wants to collect funds separately for group events or charity, then it should have its own EIN and be formed as a non-profit organization. It’s not difficult to do; the proper forms will need to be filed with the IRS, and the organization will need to create its own formation documents.