By [AUTHOR NAME, TITLE], Kelley Electrical Contracting. Published 2026-10-16. Last reviewed [DATE]. Educational information, not a substitute for an on-site inspection.
Two-prong, ungrounded outlets
Two-slot outlets usually mean there is no ground wire. Adapters do not add a ground. A licensed electrician can add grounded or GFCI-protected outlets or rewire the circuit.
Call (559) 940-1939Questions? Talk to a licensed electrician.
Knob-and-tube wiring
Found in very old homes, it uses single insulated wires run on ceramic knobs and tubes with no ground. It can be dangerous when buried in insulation or modified. Many insurers ask for it to be replaced.
Call (559) 940-1939Questions? Talk to a licensed electrician.
Aluminum branch wiring
Homes built roughly from the mid-1960s to the mid-1970s may have aluminum branch circuit wiring. Aluminum expands and contracts more than copper and connections can loosen over time, creating heat. There are approved repair methods, and an electrician can assess them.
Call (559) 940-1939Questions? Talk to a licensed electrician.
Cloth or brittle insulation and old panels
Cracked, brittle or cloth-covered wiring and certain older panel brands with known problems, such as Federal Pacific Stab-Lok and Zinsco, deserve professional evaluation.
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What to do
You do not need to panic, but you should not ignore it. An inspection can tell you what is safe to keep, what to repair and what to replace, and helps you plan upgrades such as solar, a battery or an EV charger.
Call (559) 940-1939Questions? Talk to a licensed electrician.
Frequently asked questions
Is aluminum wiring safe?
It can be if connections are made and maintained with approved methods. Have it evaluated by a licensed electrician.
Can I just replace two-prong outlets with three-prong?
Not without a ground wire or GFCI protection. A three-prong outlet with no ground is unsafe and misleading.
Does old wiring affect insurance?
Some insurers require inspection or replacement of certain old wiring. Ask your insurer.
Call (559) 940-1939Questions? Talk to a licensed electrician.
Sources and further reading
Need an electrician?
Licensed California electrical contractor, license #1111378. Serving Fresno and Madera.