Frank Hollberg III, whose family has bought furniture in Senoia, Georgia given that 1894, laughed as he recalled the abnormal sight of looking at a person walk through the idyllic downtown keeping a head in his hand. The top was a prop and the person an actor filming “The Strolling Lifeless,” the hit zombie-themed television collection that has drawn millions of fans global and helped turn the small city 25 miles south of…