I have two separate switches that service one ceiling light. This morning both switches failed to turn on the ceiling light. The bulb was checked and found to be good. The circuit breaker was still in the operational mode. I also have a wall switch that services two bulbs in my bathroom which is very close to the other above problem. The bulbs and the circuit breaker are in the working mode. Other than call an electrician, what must I do to rectify the problem?