Mich. Comp. Laws § 338.2155

Sec. 5. (1) The work of installation, alteration, maintenance, repair, servicing, inspecting, adjusting, or testing of an elevator covered by Act No. 227 of the Public Acts of 1967, shall be done by a person who is licensed by the department of labor as an elevator journeyman, or by his helpers under the immediate supervision of a licensed elevator journeyman. (2) A person entering an elevator hoistway or machine room for any reason, except under an emergency situation, shall be a licensed elevator journeyman, shall be employed as a helper and be under the supervision of a licensed elevator journeyman, or shall be commissioned as a special or general inspector. This requirement does not apply to engineering, management, or sales personnel of a licensed elevator contractor, or owner's authorized representatives.