Minn. Stat. § 325G.07: BUYER'S RIGHT TO CANCEL.

In addition to any other rights the buyer may have, the buyer has the right to cancel a home solicitation sale until midnight of the third business day after the day on which the home solicitation sale occurs. Cancellation is evidenced by the buyer giving written notice of cancellation to the seller at the address stated in the agreement or offer to purchase. Notice of cancellation, if given by mail, is effective upon deposit in a mailbox, properly addressed to the seller and postage prepaid. 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 home solicitation sale.