Ohio Rev. Code § 1345.43
In addition to any right otherwise to revoke an offer or to terminate or cancel a sale or contract, the buyer has the right to cancel a prepaid entertainment contract until midnight of the third business day after the date on which the first service under the contract is available, and if the facility or service that is the subject of the contract is not available at the time that the buyer signs the contract, the buyer has until midnight of the seventh business day after the date on which the first service under the contract is available to cancel the contract. Cancellation is evidenced by the buyer giving written notice of cancellation to the seller at the address of any facility available for use by the buyer under the contract, the seller's electronic mail address, or the seller's facsimile number. The buyer shall deliver the notice by manual delivery, personal delivery, or by certified mail delivery, return receipt requested, electronic mail, or facsimile transmission. Notice of cancellation by certified mail delivery shall be effective upon the date of post marking. Electronic mail delivery is effective when the electronic mail is sent to the seller's electronic mail address. Facsimile delivery is effective when the facsimile is sent to the seller's facsimile number and the consumer has received confirmation of the facsimile transmission. Manual delivery or personal delivery is effective when delivered to the seller or to the seller's address, whichever comes first. Notice of cancellation need not take a particular form and is sufficient if it indicates, by any form of written expression, the intention of the buyer not to be bound by the contract. Notice of the buyer's right to cancel must appear on all notes or other evidence of indebtedness given pursuant to any prepaid entertainment contract.
R.C. § 1345.43