Ohio Rev. Code § 503.09
Where a township contains a municipal corporation, either in whole or in part, if a majority of the freehold electors owning land in the portion of such a township outside the municipal corporation's corporate limits, petitions, with a map accurately setting forth such territory, praying to have such territory erected into a new township, and excluding the territory within the municipal corporation, the board of county commissioners shall enter an order erecting such territory into a new township, the boundaries of which need not include twenty-two square miles of territory. Upon the erection of such new township, the territory lying within the limits of the new municipal corporation in the original township shall be considered as not being located in any township.
R.C. § 503.09