It is my understanding that if a person who was institutionalized but has since passed that "next of kin" can get records. I know the State Archives in Lansing has a file drawer of stuff but I have never used it.
Please, Please! If you get the "burned courthouse" story from anyone, whether it be courthouse, church, school, library or otherwise, find out who you were talking to and call back another day and ask someone else. "Lazy" people, or those that don't want to be bothered, use this excuse to get rid of us crazy genealogists. This is also why contacting the local societies are so important.
Another tip: You will find lots and lots of info from the oldest person in the nursing home that wants to talk. Ask at a home in a town where you have questions in for someone who is able to talk but seldom has visitors. I do this with on occasion. Hardly any nursing homes say I can't visit someone I don't know. It helps them out as well if you think about it. I usually go away knowing things that don't pertain, but had a nice visit anyway. But I do pick up on some clues.