If they're anything like other good-sized faires (Renaissance as well as other types), yeah, it's a safe bet they're running at least security comms. If they're permanent, it's also likely they've got some kind of officially licensed channel. If the company that owns it is anything like the company around here (Bristol, Wisconsin) where the company that runs it owns multiple renaissance festivals, you might want to check where the owning company is located: if the company has their main offices off-site, the FCC info might show the company's home address (instead of the location of the fest) as the transmitting city (I've seen it happen!).