My microwave was blowing the circuit breaker. I replaced the door switches on my Bosch microwave before with the same problem. The switches couldn't be just wearing out. The "normally open" and "normally closed" switches must be tripped at the same instant. If they don't it burns the switch and trips the breaker. I noticed that there was excessive play / a loose fit of the switch in the plastic bracket attached to the door frame. I shimmed the new switch so it didn't move. That should solve the problem.