32 C.F.R. § 552.63
The Federal Trade Commission Rule, 16 CFR part 429, p. 233, effective 7 June 1974, pertains to a cooling off period for door-to-door sales. The rule applies to any sale, lease, or rental of consumer goods or services with a purchase price of $25 or more, whether under single or multiple contracts, in which the seller or business representative personally solicits the sale, including those in response to or following an invitation by the buyer, and the buyer's agreement or offer to purchase is made at a place other than the place of business of the seller. The purpose of the law is to allow the consumer the right to cancel a transaction at any time prior to midnight of the third business day after the date of the transaction. When any door-to-door sale or transaction takes place anywhere on or off the installation (other than the seller's place of business) the consumer must be provided with a full and complete receipt or copy of a contract pertaining to the sale at the time of its execution which shall include the "cancellation statements" as required by the FTC rule.
32 C.F.R. §552.63