Mich. Comp. Laws § 125.772

Sec. 2. (1) A mobile home manufactured or sold in this state or brought into this state for use therein as a dwelling shall be equipped with an approved smoke detection system with an alarm and a multipurpose fire extinguisher having a minimum 2A-10B-C rating and approved by a nationally recognized independent testing laboratory. The owner of a mobile home brought into this state for use as a dwelling shall have 90 days to comply with this act. (2) This act shall not apply to: (a) A recreational vehicle. (b) A motor home. (c) A mobile home manufactured, sold, or purchased prior to the effective date of this act.