Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.2953

(a) The will shall be made in writing, but does not need to be written by the testator personally. The will may be written in any language and may be written by hand or by any other means.

(b) The testator shall declare in the presence of 2 witnesses and an authorized individual that the document is the testator's will and that he or she knows its contents. The testator need not inform the witnesses or the authorized person of the will's contents.

(c) In the witnesses' and the authorized individual's presence, the testator shall sign the will or, if the testator has previously signed the will, shall acknowledge his or her signature.

(d) If the testator is unable to sign the international will, the absence of the testator's signature does not affect the will's validity if the testator indicates the reason for the inability and the authorized individual makes note of the reason on the will. In such a case, it is permissible, but not required, for another individual present, including a witness or the authorized individual, to sign the testator's name at the testator's direction, which act the authorized individual shall also note on the will.

(e) The witnesses and the authorized individual shall there and then attest the will by signing in the presence of the testator.