Mich. Comp. Laws § 38.460
All appointive officers and employees of the township or any department thereof at the time this act takes effect, and who have been such for more than 2 years prior thereto, whose positions are included in the classified civil service, shall hold their positions without examination until discharged, reduced, promoted or transferred, in accordance with the provisions of this act. All appointive officers and employees of the township or any department thereof included in the classified civil service by this act, who shall have been so employed for more than 1 year and less than 2 years prior to the time this act takes effect, shall be required to take qualifying examinations, and all such appointive officers and employees who shall have been so employed for less than 1 year prior to the effective date of this act shall be required to take competitive examinations. All employees now authorized by law to be employed in any township office or department for seasonal or temporary employment, who have been in such employment of the township for 2 successive seasons immediately prior to the time this act takes effect, shall be included in the classified civil service and be eligible for appointment to such seasonal or temporary occupation without examination.
MCL 38.460