In addition to all other powers now conferred by law upon county commissions, the commissions are hereby authorized to require owners, residents or occupants of factory-built homes situated in a factory-built home rental community with at least ten factory-built homes to visibly post the specific numeric portion of the address of each factory-built home on the immediate premises of the factory-built home of sufficient size to be visible from the adjoining street: Provided, That if no numeric or other specific designation of an address exists for a factory-built home subject to the authorization granted by this section, the commission has the authority to provide a numeric or other specific designation of an address for the factory-built home and require that it be posted in accordance with the authority otherwise granted by this section.