For each ghost, insert a 1/4-inch-diameter dowel into an 8-inch-diameter plastic foam ball; glue to secure. Drive the other end of the dowel into ground. Cut up both sides of a white garbage bag; lay it over the ball. Layer one yard of cheesecloth over the bag. Gather both materials below the plastic-foam ball and tie with a ribbon. Cut three ovals from adhesive-backed black felt and place on ghost's head. To make a row of ghosts, use safety pins to attach the edges of the ghosts together.