I'd been having a hard time sleeping because the dimmer I use on a
lamp for a night light whistles or makes a very high pitch, continuous
noise like a Cicada. I then move the dimmer to another location but
the sound is still there. When I face the wall during sleep the sound gets
louder. I have tinnitus so it's very hard to distinguish the two sounds
until I sleep with ear muffs. I will get rid of this problem but I haven't
found a solution since I lack sleep and not in my right mind. What are
some repair solution or products I can use to dim night lights?

Thanks