The Mayoral Candidate Forum will be on Oct. 31 at WTVI Studios, 3242 Commonwealth Ave. Filming is scheduled for 11 a.m.- Noon. The forum will be broadcast at 8:00 p.m. Oct. 31 and again on Nov. 2 and Nov. 3. If you would like to be a part of the studio audience, register here. Limited seating is available. This is…