Wyo. Stat. § 40-12-103: Unsolicited merchandise.

Unless otherwise agreed, when unsolicited merchandise is delivered to a person, he has a right to refuse such merchandise and is not obligated to return such merchandise to the sender. Such unsolicited merchandise is deemed an unconditional gift to the recipient, who may use it in any manner without any obligation to the sender. This section does not apply if there is evidence that the merchandise has been misdelivered, or if the delivered merchandise is offered as a good faith substitution for merchandise previously solicited by the recipient.