My bathroom vanity light will not turn on. I have tested the plugs surrounding the switch and the fan switch and they are all hot. I have reset the breaker and reset all of the GFI's but nothing seems to help to make this work. What can I do to fix this. Is it just a switch gone bad or is it something more?

After checking everything you already have, its most likely the switch itself, like you are thinking.

Do you have a multi-meter?

If you do, test the feed into the switch with the switch in the OFF position.

If the power source to the switch is from the ceiling, then you should be getting 120 V +/- at the bottom of the switch. If not, you will need to get behind the canopy for the light fixture and make sure there are no loose connections.

If the feed to the switch is direct, then you to follow the circuit backwards.

If you set the switch on, then you should have the 120 V at the return side of the switch.

If you have power to the bottom of the switch and no power at the top of the switch, replace the switch.

Thank you for the assurance! I will try this tomorrow as it is late tonight. If this works, then you will hear nothing further from me on this but if not I will be tracking you back down for more assistance. Again, thank you!