How to figure out if your house has old knob-and-tube wiring. If you look at your outlets in your house and they only have two prongs, meaning that there's only two entrances and there's not a third one, there's a good chance that your outlet isn't grounded, and that directly correlates with your house being old knob-and-tube wiring.
Being in the Bay Area, there's a good chance that your wiring was done 80 to even 120 years ago when knob-and-tube was the best option. Nowadays, we know that knob-and-tube could pose a fire risk because of the insulation that could break away. Nowadays, we know that knob-and-tube can pose a fire risk. Because of its insulation that's very any time that it's disturbed, there's a good chance it could break off, and that could cause a fire risk when it comes in contact with insulation.
So any time you're gonna have new insulation put in your attic, always make sure you have no knob-and-tube in your home. In addition to that, knob-and-tube is ungrounded. That means that it's missing the modern-day protection of being grounded. Another problem with knob-and-tube is that a lot of insurance will not insure your home if you have knob-and-tube. Knob-and-tube is known for its fire risk, and insurers do not wanna hold that liability. The solution to knob-and-tube is to rewire your house and make sure you're properly grounded to protect your house.