Occasionally House Lights "Twitch"

Lately I have been noticing our house lights will briefly dim or "twitch". I really noticed it while remodling our bathroom because of the bright lights and white room. There is no pattern to it and I have turned off a dehumidfier thinking that was causing the twitch - not the case. I have added some lighting in the house but this is basic lighting and a switch. I have used ROMEX 12 and 14 on the same line but that should be okay. Where could I start to look to determine what might be causing the lights to do this? The TV and other appliances are not affected.

 

There may or may not be anything wrong. But I'd start by looking at all the connections, especially of the white wire, on all outlets on all circuits that may be experiencing light flicker. If any of the connections are using backstabs, move them to the adjacent screws. Make sure all wire nuts are very tight. Then have a qualified person tighten connections in the panel. If all that fails, call your power company and ask them to investigate voltage fluctuations. You may have an undersized or malfunctioning transformer, undersized wires feeding your house, or a bad connection on the power company's side of the supply.

It takes very little voltage dip to cause an incandescent light to flicker, especially to a sensitive eye. Any time you turn on more load, there will be some voltage dip on the circuit. In most situations, this is barely noticeable. However, when you turn on a vacuum cleaner, or any other large motor, on a circuit that also has lighting, almost everyone will notice that flicker -- especially if the load is quite a distance from the panel.

 

The light "dimming" is occurring throughout the house. I have noticed it with the lighting and a box fan will make a slight change in sound as well when it occurs, these are on separate circuits. My spouse does not notice it as much as I do. Our house was upgrade 4 years ago by the electric co. for voltage to the house.

The light switch I am using in the bathroom uses backstab connections but does not have screw connectors because it is a three connector switch (1 shower light/fan, 1 bath recessed lights, and 1 for wall sconce lighting).

I will contact my electric company and ask them to test our connectivity to the source.

Thank you.