Hello

I currently have a garbage disposal. There is a switched ac duplex outlet in the cabinet under the kitchen sink that the garbage disposal plug into. In my backsplash there is a wall mount switch that switches the outlet. This is the original installation. Home is on the San Francisco Peninsula, ranch style built in the mid 1950s.

The kitchen does not have a dish washer. I am going to cut out a cabinet and install a dishwasher.

The issue is the power needed for the dishwasher. The wiring is original knob and tube and I am not planning on opening the walls etc. The outlet is currently switched for the disposer however I need constant power for the dishwasher.

I was thinking if I could pull a wire off the hot side of the wall mounted switch that I could break the tab off the duplex outlet I could have one of the receptacles switched and the other constant. However I am not opening the walls and there is no conduit to pull a wire as it is knob and tube.

The only idea I have is to purchase an insinkerator counter top air switch. This way I could leave the wall mounted switch in the on position all the time to satisfy the dishwasher and also plug in the air switch and control the disposer from the air switches counter top switch. Is this my best solution?

Are there any tricks or cleaver ideas that would work that I am not aware of?

Thanks

The outlet for the GD is commonly the 'always hot' source, with a switch loop run to the wall switch.
There s then no reason to pull for the DW from the switch, it is already present in the junction box for the GD under the sink.

You do need to make sure you are not going to further overload the old K&T wiring though.
It was generally never envisioned for anything approaching a modern kitchen load (and not just the pair of20 amp small appliance branch circuits) but the actual power demand of toaster ovens, microwaves, and other large heating appliances.

There are a LOT of insurance companies out there that won't even insure a home with K&T. And the main reason is that homeowners like to up their electrical demands on the wiring by hacking at it without replacing the K&T, which leads to fires. This is NOT a path you want to go down. Either leave the K&T completely alone, and that means no cramming in insulation around it or trying to use it to further extend or alter a circuit, or rip it all out and have the home completely rewired. If you are attempting to put a modern kitchen in this home, then the best approach is to rewire for that kitchen. Don't touch that K&T!

The insurance company war against K&T is stupid on its face.

Maybe they were just behind the times but I have never heard of a house built in the '50s that had K&T. I would be surprised if there was already a receptacle under the sink when the house was built. However, I believe disposals began showing up in the late '30s or early '40s.

Ditto... something doesn't jibe.

OTOH, if it really was built in the mid-1950s, is it the Modern style known as "Atomic Ranch"? Those can be GREAT homes in NorCal...