What's Hidden Behind Your Walls: The Lifespan of Electrical Wiring

Most homeowners rarely think about the wiring inside their walls — yet it’s one of the most important systems in any home. Over time, just like plumbing or roofing, electrical wiring can wear out, loosen, or become unsafe. Understanding how long wiring lasts, what signs of aging to watch for, and when to upgrade can help prevent costly damage or electrical fires down the line.

Modern copper wiring can last anywhere from 50 to 70 years if it’s installed properly and kept dry. However, not all homes have modern wiring. Houses built before the 1970s may still use **aluminum wiring**, which was common at the time but is now known to expand and contract with temperature changes. That movement can loosen connections, create arcing, and pose a serious fire hazard if not updated or properly maintained. Even older homes built before the 1950s might still have **knob-and-tube wiring**, which lacks grounding and insulation by today’s standards.

The insulation around wires can also degrade over time, especially in hot attics, damp basements, or areas exposed to pests. Brittle or cracked insulation allows electricity to escape and potentially make contact with surrounding surfaces — something that should never be ignored. In addition, renovations, drilling, or DIY work can sometimes damage hidden wiring without homeowners realizing it.

Some telltale signs that your wiring may need attention include flickering lights, buzzing outlets, frequent tripped breakers, or a burning smell near switches or outlets. If you’ve added more appliances or smart home devices over the years, your existing wiring might also be struggling to handle the increased demand.

A professional electrical inspection can reveal the condition of your wiring and determine whether it’s still safe or needs partial or full replacement. Upgrading old wiring not only improves safety but also ensures your system can support modern appliances and future technology. Behind every light switch, outlet, and device is a network of wiring working hard to keep your home running — make sure it’s up to the task.