Have been looking for information on 2 ancesters that were commited there, one from paternal side the other from maternal side.
Be prepared for the confusion you will go through in the process as you will see when I explain.
Further note that no personal information will be found only that in the process you may find connections to another individual you maybe able to contact for any information they may be willing to give you about that individual. So don't miss anything on anything you are looking at.

In my search I found the Kalamazoo county probate records.
With a case number or individual name search you may be able to see a small portion of information.
For example the person that had your family member committed had to file paperwork (if it was involuntary commitment in any form such as not agreeing to the treatment plan) with the court system. Usually in the county they lived in (however once the patient becomes a ward the filings are then submitted in the county of that hospital).
I would search the last name of the patient. The last name of known family members, trust and estate companies, guardian companies of the time period for example Comerica Bank was listed (in conservator of an adult, fiduciary, gaurdian of an adult ect...) because all paperwork submitted for GA (guardian adult) GM (minor) had to be served to that individual (patient) also had to be served to person of principal care (hospital, foster care or private care, lawyers, person of trust) the spouse of that individual and adult children or the next known family.
Just as in regular court proceedings in any case felony misdemeanor gaurdian custody.... 3 different people receive filing copies. Court. The person and the representative.
In the case of GA there are ANNUAL REPORTS filed atleast once every year, on that ward (michigancourt rule) to protect the wellbeing of that individual. Meaning someone has to check on them and file a report with the court that they did check on them. Further, notices are sent to the original person who filed.
So there will be a paper trail on individuals its a matter of finding out who put them there and who then became responsible for them.
In these cases that person will never be specifically named any where in the public document so specific year is important when reading information
The public court documents I have seen only showed the original person to file and who became the guardian. In my family case they were listed as guardian inc,, address was available. It never listed the hospital.
In that document it showed that annual reports were filed on each date. Any motions that had been filed and each time reports were filed on the ward. Change of venue requests. Reading into the filings I found the case number the judge the parties. Ect...
I further searched that case number specifically.
I further searched cases submitted by the companies listed. Searched cases submitted by the lawyers listed
I especially searched the change of venue motions.
I further found a case listed with a slightly different number and found that to be submitted by an individual such as a foster parent. For example i searched a GA company case submitted as number 111110051 compared to another case number submitted by that same company as 111110055 around the same year date I looked into that case and found it linked to an individual which i believe to have been the adult foster care. Included address.
Don't give up searching it just becomes a matter of taking notes on every item motion reports date name and company to ensure nothing will be missed.
Once enough information has been gathered you can search public librarys for information about parties listed and eventually you will find ways to contact those people.