HEMPSTEAD - A Nassau County groundskeeper is accused of selling school property for cash.Police say Hempstead School District's supervising groundskeeper Johnie Tyson stole playground equipment and fencing material for scrap metal.The Nassau County District Attorney says Tyson had other staff members help him haul the stolen property.Materials cost about $50,000 to replace, and Tyson could face up to seven years in prison if he's convicted.