Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.2515

Sec. 2515. (1) A will in writing that is enclosed in a sealed wrapper, on which is endorsed the testator's name, place of residence, and social security number or state of Michigan driver's license number, if any, and the day on which and the name of the person by whom it is delivered, may be deposited by the individual making the will, or by a person for him or her, with the court in the county where the testator resides. The court shall receive and safely keep the will and give a certificate of the deposit of the will. For this service, the court shall charge and collect a fee as provided by supreme court rule or the revised judicature act of 1961.

(2) During the lifetime of the testator, the will shall be delivered only to the testator, or to some person authorized by the testator in writing that is duly proved by the oath of a subscribing witness. After the death of the testator and at the first session of the court after the court receives notice of the testator's death, the will shall be publicly opened and retained by the court.

(3) After the death of the testator, if jurisdiction of the will for probate belongs to a court in another county, upon request of the personal representative named in the will or another person interested in its provisions, the will shall be forwarded by registered mail to the other court or delivered to the personal representative, or to some other person interested in the provisions of the will, to be presented for probate in the other court.