The same electrical wire to the fuse box comes from guest bathroom (2nd flr) and the master bedroom's bathroom. The circuit breaker on the fuse box had 15amps. If my daughter and my wife use the hair dryer at the same time, the circuit breaker on the fuse box got tripped. If my daughter uses the hair dryer and I use the bathroom with the light/fan, it got tripped, too. I tried to change the circuit breaker to 20 amps but it didn't help. How can I fix that? Do I need to re-wire the electrical wire for the guest bathroom? FYI: The guest bathroom has an outlet with circuit breaker built-in (it didn't work). Please help! Thank you very much.