Mich. Comp. Laws § 445.105

Sec. 5. It shall be an unlawful trade practice for any person engaged in selling goods, wares, or merchandise to individual consumers, to incorporate in his business name or otherwise to use in describing his business, the words "manufacturer,""miller,""wholesaler,""broker," or any derivative or synonym for any of them, unless such person is in fact engaged in 1 or more of such businesses in addition to his business of selling goods, wares, or merchandise to individual consumers. In cases where a person is engaged in manufacturing, milling, wholesaling, or brokerage and is in addition engaged in making sales to individual consumers, it shall be an unlawful trade practice for such person to imply directly or indirectly in connection with sales to individual consumers that the selling price is other than a retail price unless the sale is for resale.