Whole house flicker under load (when the AC or a large appliance starts) points at the service: the connections at the meter, the mast, or the utility's own feed and neutral. A failing utility neutral is the serious version and it is the utility's repair, free to you, but it must be reported and it can damage electronics while it lasts. Flicker on one circuit is the home's side: a loose connection at a device or in the panel. An assessment that meters the service under load separates the two in one visit, and honest electricians check the utility side before quoting you a panel.
Prefer to talk later? Leave your details and an independent local pro will call you back. No charge to you, no obligation.
San Lorenzo Electric is a free referral service. Submitting this form connects you with independent local contractors who provide the work.