Combine soup mix and milk; let stand 5 minutes. Add ground beef and egg to soup mixture; stir until mixed well. Shape into 1-1/2-inch balls. In large skillet brown meatballs in hot oil; drain. Return meatballs to skillet. Stir in spaghetti sauce; bring to a boil. Reduce heat; cover and simmer over medium heat 15 minutes. While sauce is simmering, cook spaghetti as package directs, omitting salt; drain. Serve sauce and meatballs over spaghetti.