Good Morning,
I hope someone out there knows the answer to this!
We have electric heat baseboards (as backup heat source) in our bedrooms and living room. We heat with a woodstove, so they are always turned as low as possible, unfortunately, there is no off setting.
The bedroom baseboard has an annoying vibrating buzz, (similar to the sound of "dead air time" on a radio) even though it is completely cold to the touch. It used to stop when I gently tapped it. Lately, it just starts buzzing or humming again within a few seconds. It's one of those little noises that just drive you nuts in the middle of an otherwise quiet night! We have tried tightening the bolts/screws. Is there a way to disconnect the wires safely? If that is not a safe option, does anyone have any other suggestions? The only other thing I can say about it is that it works perfectly, and stops buzzing when in use at about a 65 degree setting, but with the high cost of electricity... leaving it on all night is just not an option. The same type of baseboards are located throughout the house, but I haven't ever noticed the same noises from anywhere but the bedroom.
I would certainly appreciate any comments or suggestions on this little problem!
Thanks so much, and have a great day.

You can replace you switch with one that does have an off position. I'm having difficulty picturing yours doesn't have an off. There is vibration caused by current passing through heating element. If you start touching fins and brackets you should eventually find something that's allowing the vibration. Clamp it tighter. In the meantime, shut off the breaker at night, it is most likely dedicated to your electric heaters only.

Here are some previous answers I gave for a similar problem:

https://www.askmehelpdesk.com/electrical-lighting/baseboard-electric-heater-buzz-hum-45561.html?highlight=electric+baseboard

https://www.askmehelpdesk.com/electrical-lighting/buzz-humm-electric-baseboard-heater-49071.html?highlight=electric+baseboard

Let me know if these do not help.