Beneath a mahogany staircase inside the Sandusky County Historical Society hangs a memorial plaque in a place both fitting and strange. The sanctuary is gone. The Torah scrolls have long since been moved elsewhere. Military exhibits and county memorabilia fill the rooms. But the plaque remains, listing the dead of Temple Beth Israel, a congregation that closed more than four decades ago. Across Ohio, when small-town synagogues closed, their hist…