Some bad movies should carry a leper’s bell to warn off ticket buyers. Such a contagion is Charlie St. Cloud, a load of mawkish swill starring Zac Efron (bereft of the talent he showed in Me and Orson Welles). As Charlie, Efron plays catch every day at sunset with his younger brother, Sam (Charlie Tahan). The problem? Sam died in a car accident. Director Burr Steers, who guided Efron through the witless 17 Again, bathes this mush in golden light. But you can’t shine a turd. Charlie falls in love with a pretty sailor (Amanda Crew). But even she’s half dead. The movie is dead on arrival.