Mich. Comp. Laws § 558.81
Claim of dower; filing, contents.
All persons having or claiming dower, whether inchoate or consummate, in lands conveyed, or otherwise disposed of, more than 25 years prior to the time this act shall take effect, by the person who is or was the husband of the person claiming such dower, shall, within 6 months after this act shall take effect, file in…