In alt.home.repair, on Sun, 17 Nov 2019 18:51:58 -0500, micky
wrote:

In alt.home.repair, on Sun, 17 Nov 2019 22:14:03 +0000, Jake Chominsky
om wrote:

I have an 1950’s home with older wiring. Most of the house only has a black
and white wire connecting to lights and recepticals. I want to do a 3-way
switch. Currently, the power is coming in through the light then connecting to
the on/off switch. How could I install a 3-way if I can only add a new wired
line from a new switch (#2) to the current light and also cannot upgrade or
touch the existing wired line from the current switch to the current the
current light? The reason I cannot touch the existing line is because it is
behind 2x4s and walls where’d I have to demo a wall which is outside of my
capabilities.

What floor is the switch on? How many floors in the house? Finished
ceiling in the basement? Finished floor in the attic?

You may or may not not need to demo anything to run another wire, but
answer the 4 quewtions above.

Jake, you haven't answered. Do you want to khow how you may be able to
add your switch without demo, or not?

Ken's wiring diagrams are very good. The one that's best for you
depends on the answer to the 4 questions above.