OP:
My home was about 15 years old when I moved in and suffered from several non-code compliance issues as well as lighting gremlins. A complete replacement of every single switch and all the 120V breakers really cleaned things up.
The old rotary dimmers are especially noisy things, and I strongly recommend replacement with a modern home automation dimmer which, believe it or not, are a lot less noisy on the line and physically. They also handle LED lights really well.
https://amzn.to/45taCMx
