A new museum of police and firefighter artifacts is set to open to the public on Thursday. Located at 1 School St. in a 19th-century schoolhouse, the Sharon Police and Fire Museum holds items from local departments and from Boston, Chicago, Minneapolis, and New York, said Sharon’s deputy police chief, John “J.J.” McGrath. Among the Sharon items are the hat, badge, billy club, and handcuffs used by Sharon’s first official police chief, Hervey Derry, ancestor of current patrolman Richard Derry. The museum welcomed 76 Sharon third-graders for a tour on June 7. “It’s really satisfying to see people come in and enjoy it,” McGrath said. He and police Lieutenant John Ford and their wives collected items and prepared the space, he said. Hours are Thursdays from 3 to 5 p.m. The museum will also be open Sundays, but hours have not yet been finalized. Admission is free.