VATICAN CITY (AP) — The death of a pope starts a centuries-old ritual involving sacred oaths by the cardinals electing a successor, the piercing of ballots with a needle and thread after they’re counted, and then burning them to produce either the white or black smoke to signal if there’s a new leader for the world’s 1.3 billion Catholics. The election itself is shrouded in secrecy, with cardinals forbidden from communicating with the outside world what happened during the voting in the conclave behind the frescoed walls of the Sistine Chapel. St. John Paul II rewrote the regulations on papal elections in a 1996 document that remains largely in force, though Pope Benedict XVI amended it twice before he resigned. Here is what happens when a pope dies, a period…