Ohio Rev. Code Ann. § 4927.19
(A) The public utilities commission may investigate or examine the books, records, or practices of any telephone company, but only to the extent of the commission's jurisdiction over the company under sections 4927.01 to 4927.21 of the Revised Code. Subject to that limitation, the commission may do any of the following:
(B) The commission may investigate or inspect the plant and facility of any telephone company, subject to the following limitations: