This happens randomly. We are in Vancouver, Canada, It happens with all the lights with the same circuit, but lights are in different rooms (living room, kitchen, den and bathroom). Sometimes those lights go dim, very dim for no reason. And rarely they all blinking blank and bright like disco lights (see this video. https://youtu.be/OUrnFzoIUNw)
Most of the time they are stable. Some lights on the same circuit go very dim (50%), other lights stay stable, or flicker a bit. The lightbulbs are incandescent and LED, no dimmer in the house. This happens with just the fridge running. We weren't using microwave, or stove, or dryer, or vacuuming or running anything big.
What we have done:
Power company came and checked the wire to the poles, they said all look good to them. If still flickers, call electrician.
We did precisely just that. He checked the main panel, tighten all the breakers. Nothing replaced because all look fine.
The breakers rarely trips, although we might be running a lot in the house. it's 100Amps, we have three fridges, three stoves and two microwaves. But electrician confirmed it's not over loading, since main breaker never tripped.
He recommended opening all the outlets and switches looking for loose connection.
So we had electrician came, I have spent over $1000 and so far nothing conclusive. We are 60% through replacing outlets and switches, flicking continues and even worst.
So I am looking for some advice on line.
Because I don’t live in the house I had to go back and stay around and observe the issue. Now it’s clear to me that not just the lights on the same circuit but rather multiply circuits. So I suspect when all the lights are on in the house they might all flicker at the same time. I am asking people here to turn on all the lights and observe. If this were the case does it make sense to proceed to replace outlets and switches looking for loose connection? Or a bigger underlying issue? Thanks again