Electrical Wiring in the Home/Burnt Wiring?



Hello, Greg. I was recently in my attic and noticed what appeared to be a burn mark along a piece of cable. When I moved closer for a look, I noticed that the paper-back insulation (once covering the cable) had been pulled back. On the underside of the insulation, there is a corresponding scorch mark. See pictures. This stretch of wire is about two feet from where it enters the wall and then on to an outdoor security light. Do you know what could cause this to happen? A short? A bad fixture? It's likely been like this for several years, since I didn't move any insulation when we moved in. My though is to replace the cable.

That is a sign that the circuit is being overloaded for the wire size.

You want to replace that cable ASAP.

You also want to determine what you are using on that circuit.
It may be that you need to split that circuit with another new circuit.

You do not want to overload the new cable.

A short tends to trip the breaker, but it depends on what kind of short it is.

So you want to install a new breaker on that circuit just to be safe.

If you have access to an amp meter you can turn everything on that circuit and see how many amps you are pulling.

Glad you caught that before the attic went up in flames.  Please take this very serious, and have all your circuits checked.  
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

All Answers

Answers by Expert:

Ask Experts


Greg Hughes


Troubleshooting electrical including appliances and HVAC.


34 years of experience.

Both college and tech schools in this field.

©2017 About.com. All rights reserved.

[an error occurred while processing this directive]