Below is another photo of a situation that is frustrating to the home inspector. To begin with, as real estate professionals I imagine everyone here knows that knob and tube wiring is a concern in older houses. I am not saying it is automatically going to cause a fire, or is necessarily unsafe, but knob and tube systems are old-fashioned, do not have the equipment ground wire that is standard today and the circuits are old enough that almost always they have been cut, spliced and otherwise butchered and damaged by incompetent homeowners. Add to that, most major insurance companies either will not insure knob and tube, or they get a premium price for doing so. Therefore, a home inspector really tries to determine if active knob and tube is present in an older home (typically 1920's to 1950). Clues include two prong outlets and the porcelain knobs and tubes in attics and under houses.
The photo below was a frustrating inspection. The home was the correct age to have knob and tube. There was zero attic access and I did not see knob and tube in the crawl space. Instead, it was an early two conductor sheathed cable visible in the crawl space. In the main panel there was primarily new Romex and the early two conductor cable. However, one circuit looked like it might be old knob and tube wires. Then I went out to the garage which was the same vintage as the house. What do I see? I saw three different locations with old knob and tube circuits. They were abandoned but were evidence that the property did have knob and tube at one time. Bottom line: Especially with no attic access, and with the number of two prong outlets, I could not verify if the home had active knob and tube wiring or not. It was, at best, suspect. In such a case, about all the inspector can do is state the facts and suggest further evaluation by a licensed electrician. A garage photo is below.
Thanks for looking.
Bellingham WA home inspector