Don't touch that dial! The Post-Meridian Radio Players are back with a spine-tingler of a Halloween show, Monster in the Mirror. Utilizing expressive voice acting and hair-raising sound effects, the Players present two original adaptations of gothic tales: "The Strange Case of Dr. Jekyll and Mr. Hyde" and "The Frankenstein Murders." As Boston's "premier radio drama troupe," PMRP features actors in front of microphones while experts perform sound effects live on stage, using methods perfected during the Golden Age of Radio. This is a seasonal treat that must be heard to believed. Martha Putnam Sites hosts the show at Responsible Grace Church.