I was recently up in my attic and found an old type of wiring I have never seen before. There are glass pieces the wires are threaded through and the wires look smaller then wires we use today. What type of wiring is this and is it safe?

You are looking at an old type of wire called knob and tube. I could be wrong but I don’t believe there are any regulations that say it must be replaced. Having said that I can say insurance companies do not like it as it is a higher risk for fire then our newer lumex wire. Another issue with knob and tube is that it is not a grounded system. Today’s wire has three wires, a positive, neutral and ground. The ground wire is there to provide a path to the ground should any electricity stray from its intended path. For instance, if you were using an electric drill and stepped into a puddle of water the electricity may travel through your body. With a proper ground system it would be less likely that this would happen as the electricity always travels the best or easiest path and your body would not usually be that path. Many two wire systems look to be grounded when they are not. This is hazardous to both your health and your electrical appliances. This picture shows an insulator that used to hold the knob and tube wire in the attic. As you can see the attic was on fire at some point and an educated guess tells me it was started with the knob and tube. I am not suggesting that all knob and tube will catch fire, only that some will and that it is more likely to then today’s lumex wire. Don’t believe me, just call an insurance company to see what they think. knob and tube wire - fire

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