Mich. Comp. Laws § 408.474: Withholding payment of compensation due as fringe benefit to be paid at termination date.

Sec. 4.

An employer shall not withhold a payment of compensation due an employee as a fringe benefit to be paid at a termination date unless the withholding is agreed upon by written contract or a signed statement obtained with the full and free consent of the employee without intimidation or fear of discharge for refusing to agree to the withholding of the benefit.