Help! The vanity lights in both of my bathrooms are not working. The one in my master went out first. It uses the mercury bulbs. I tried switching the bulb, but it didn't work. The vanity light in my guest bathroom is the same, so I tried the original bulb from the master (to check if the problem was the bulb or the actual light fixture) in the guest bathroom. The light turned on for a second then back off. Now, when I put the original guest bathroom bulb or a new bulb I bought back in, neither works. Does that sound confusing? Anyway, it's not a bulb issue. Both bathrooms have another light over the bathtub, and that light works and so do the outlets. I've tried resetting the switches and the breakers but that hasn't changed anything. Could a bulb blow out a whole light fixture? Any suggestions?

I'm not an electrician, but try this.

Remove the switch cover and check the connections, all 3. If the wires are just inserted into their respective holes, (black & white), that may be the problem. Remove them, (may need to cut), and wrap around the screws instead. Be sure to identify which circuit and shut off before cutting etc.

If once the black & white are wrapped around the screw and it still isn't working, it's because the outlet that feeds this switch does not have a good connect. Repeat the steps on that outlet. You will have to search where the feed comes in other nearby room. It is normal for the different lights and outlets in a room not be on the same circuit. So as you said one light may not work while another in the same room will work fine.

Jaz

Have you done any testing to confirm there is power to the switch and then coming from the switch? Just noticed this is old so maybe you have found a fix by now.