What will happen when the current is too high for a switch?
Switch damage due to excess current goes one of 3 ways:

1) If the damage occurs as the switch is opening (which is the common failure condition when dealing with motors and solenoids) the switch contacts burn out, and the switch will no longer close the circuit.

2) If the damage occurs as the switch is closing (which is likely when switching resistive or capacitive loads) the contacts may weld together, and opening the switch to cut off power becomes impossible.

3) In either case, a middle ground sometimes occurs, and the switch behaves as a (relatively) high resistance - that is, high enough to dissipate considerable power but low enough not to limit the current appreciably. In this case the switch may catch fire or blow up.