You almost certainly wouldn't find knob & tube wiring in a 1961 house.
There is nothing inherently wrong with it, but it did require real
workmanship to install properly and due to the insulation used had a
low temperature rating. To meet code it must be installed in free air
movement. When covered with thermal insulation, it no longer meets
the temperature rating required. In extreme cases, the heat could
build up and cause a fire in the wire insulation or surroundig
materials. In fact, knob & tube could still be installed in certain
cases and meet code.

Dan

On Thu, 07 Oct 2004 23:14:52 GMT, "Stormin Mormon"
wrote:

I've seen this exactly once. It's when the old guys used to use porcelean
insulators, nailed in. They would string the wire from porcelean to
porcelean.

Sometimes seen in very old barns.