Peter Debruge Chief Film CriticErica Wigg, the main character of Goro Miyazaki’s made-for-TV feature “Earwig and the Witch,” is both a brat and an orphan. Those two traits seldom go together in children’s stories, and the combination provides a modest starting point for this intermittently amusing CG entry from Studio Ghibli — back in business but a shadow of its former glory.