Here's some info about Plain City.
The village sits in both Madison & Union Counties. All 9-1-1 calls made from land lines in the village no matter what side of the line you are on go to Madison County. The Madison County Sheriff's Office dispatches Pleasant Valley Fire. The Union County Sheriff's Office dispatches Plain City Police.
Union County can and does dispatch Pleasant Valley Fire on the Union County Fire channel then Madison County has to redispatch it on the Pleasant Valley Fire channel. Madison County can and does dispatch Plain City Police on the Madison County Sheriff channel then relays the info to Union County via phone. Most of the time though, Madison will just transfer the call to Union County and stay out of the middle of it.
Plain City Police is dispatched on the Union County SO1 MARCS talkgroup. Pleasant Valley Fire has their own VHF repeater (154.445MHz)
Pleasant Valley Fire covers the Villages of Plain City, Kileville & Unionville Center plus Canaan, Darby & half of Pike Twp (E/O Rosedale Milford Center Rd) in Madison County and a third of Darby Twp (the PC phone exchange) in Union County.
Any other questions you may have, ask me - I probably know the answer or can find it!