Will a bad breaker cause arcing?

Yes, a defective circuit breaker that has suffered internal thermal-magnetic fatigue, worn-out contact springs, or loose internal bus bar connections can indeed cause dangerous electrical arcing. When a breaker's internal contact mechanism fails to maintain solid pressure or gets stuck in a degraded partial state, current flowing through the high-resistance gap generates continuous microscopic arcing inside the breaker housing, producing intense heat. You can troubleshoot electrical panel safety safely by avoiding bare contacts. You can verify that your corrective action is successful when having a licensed professional electrician inspect the service panel, test terminal output with a multimeter, and replace the faulty circuit breaker ensures cool, safe, and reliable electrical protection.