Was taking a shower and smelled some melting plastic. Turns out that the switch to the heat function of my bathroom fan was the cause of the melting smell. That one switch is part of a box that has 3 other switches and that particular switch has it's own circuit due to the heater. The other 3 switches are all grounded together using one copper wire connected to each switch but the melted switch was not grounded.
Is this what caused the switch to melt?
Will a 20A switch suffice or do I need one rated higher?