The Biggest Home Wiring Mistake You're Making and How to Fix It Fast


Home electrical wiring is complicated and mistakes can be dangerous. As a homeowner, I want to keep my home and family safe. In this article, I will discuss the biggest wiring mistake homeowners make and explain how to fix it quickly.

Using the Wrong Wire Gauge

The biggest wiring mistake I see homeowners make is using the wrong wire gauge for circuits.

What Wire Gauge Is

Why Wire Gauge Matters

Choosing the Right Wire Gauge

Checking Your Home's Wiring

To make sure I'm using the right wire gauge in my home electrical system, here are some steps I take:

1. Turn Off Power

Safety first! Turn off the circuit breaker for the wires I plan to inspect. Verify power is off with a non-contact voltage tester.

2. Remove Outlet/Switch Cover

Take off the cover plate and unscrew the outlet/switch from the electrical box to access the wires.

3. Check Wire Labels

Inspect the insulation labeling on the wires and verify they match the circuit breaker (e.g. 14 AWG for a 15A breaker).

4. Check Wire Colors

Proper wire colors indicate proper gauges. For example, 14 AWG wires are typically white or yellow.

5. Replace Any Underrated Wires

If any wires are undersized for the circuit, they must be replaced with thicker wires of the proper gauge.

Fixing Underrated Wiring

If I find any circuits wired with undersized conductors, here are the steps I take to fix it:

1. Turn Off Power at Breaker

Kill power to the circuit at the breaker panel before working.

2. Remove Old Wires

Take out the incorrectly rated wires from the outlets, switches and junction boxes.

3. Install New Wires

Run new, thicker wires of the proper gauge through the system. Match wire colors to maintain proper hot/neutral/ground.

4. Update Breaker if Needed

For severe undersizing, the circuit breaker may also need to be replaced with a lower amperage rating.

5. Test Circuit

Turn the power back on and test that the circuit works correctly with no shorts or faults.


Using wiring that is too small is extremely unsafe and the leading cause of electrical fires. As a homeowner, I must take care to use the proper wire gauge matched to my home's breakers. Checking my existing wiring and upgrading any underrated conductors is crucial for preventing catastrophe down the road. With the right wire thickness, I can keep my home's electrical system running safely and smoothly for years to come.