Susan and Evan Stitt’s farmhouse in Senoia, Ga., is nestled in a neighborhood of classic Southern homes with wraparound porches, gas lamps and tree-lined sidewalks so picturesque, it might be a film set.

In fact, it is. The Stitts, who paid $575,000 for their four-bedroom home in 2013, live in the Gin Property, a new upscale development an hour from Atlanta. The community so convincingly captures the essence of a quaint small town that producers of AMC’s “The Walking Dead” leased the entire development as the setting for...