Mich. Comp. Laws § 554.604

Sec. 4. (1) The security deposit shall be deposited in a regulated financial institution. A landlord may use the moneys so deposited for any purposes he desires if he deposits with the secretary of state a cash bond or surety bond written by a surety company licensed to do business in this state and acceptable to the attorney general to secure the entire deposits up to $50,000.00 and 25% of any amount exceeding $50,000.00. The attorney general may find a bond unacceptable based only upon reasonable criteria relating to the sufficiency of the bond, and shall notify the landlord in writing of his reasons for the unacceptability of the bond. (2) The bond shall be for the benefit of persons making security deposits with the landlord. A person for whose benefit the bond is written or his legal representative may bring an action in the district, common pleas or municipal court where the landlord resides or does business for collection on the bond.