I often hear other radio systems come across TG 17744 all because of the patch.
Many times one department is patched to another,to another etc....If the comm center doesn't drop the patch it can be interesting.
During the summer I often hear comm's for Pocono Raceway as well as Hershey Park(usually for a big concert) . Most of the time it is for traffic control,but not always.
This is also true when the city patches Fire tac-2 with a county FG freq. (normally during a large brush/mountain fire). You never know what FD you might hear.
Charlie/Reading,PA