Mich. Comp. Laws § 556.206

Sec. 106. (1) A power of attorney executed in this state is valid in this state if, when the power was executed, the execution complied with the requirements for the execution of a power of attorney under the law of this state as it existed at that time. (2) A power of attorney that is not executed in this state is valid in this state if, when the power was executed, the execution complied with either of the following: (a) The requirements for the execution of a power of attorney under the law of the jurisdiction that determines the meaning and effect of the power under section 107 or under the law of the jurisdiction in which the principal was domiciled at the time of execution. (b) The requirements for a military power of attorney under 10 USC 1044b. (3) Except as otherwise provided in the power of attorney or by statute other than this act, a photocopy or electronically transmitted copy of an original power of attorney has the same effect as the original.