The Stoneham Chamber of Commerce is seeking exhibitors for its annual Health & Wellness Expo, scheduled for 9 a.m. to 2 p.m. May 4 at the Stoneham Middle School, 101 Central St. The expo will offer free health screenings and demonstrations of martial arts, belly dancing, and music and movement. There will also be children’s activities and contests, and Boston Red Sox mascot Wally the Green Monster will be on hand to have his picture taken with youngsters. The event’s title sponsor is Stop & Shop. Other sponsors include StonehamBank, Hallmark Health System, and Winchester Hospital. Businesses that would like to participate can call the chamber at 781-438-0001. Exhibitor fees are $50 for chamber members and $75 for nonmembers.