Milwaukee Mystery Badge

Here is one of my mystery items that came to me via the internet a number of years ago. The badge is inscribed “NATIONAL CONVALESCENT HOSPITAL” on the star design with “SECURITY OFFICER” and the number 9 above and below. A Google search lists this hospital name as being in Milwaukee and only gives the hospital location as Lat. 43.05 and Long. 87.92 ! As close as I can figure it that is the former location of the long defunct St. Anthony’s Hospital. None of my old timer Milwaukee friends has ever heard of the Nat. Conval. Hospital. St. Anthony’s was a truly charitable hospital that served the poor of that neighborhood right into bankruptcy. The badge looks like it could be circa 1920’s and makes me think there may have been so sort of federal connection there for veterans or victims of the flu epidemic. If anyone here knows please let us hear from you.