I need to install a 3-way switch for a stairway. I want to avoid tearing out the wall. Right now there is a switch at the top of the stairs that operates a light at the bottom, but that's it. I'd like to replace that switch with a 3-way switch and add a 3-way switch at the bottom. I should be able to get the bottom one in with little demolition. Is it possible to pull new 3-way wiring through existing conduit for the switch at the top? House was built in 1931. Wiring is metal conduit with two wires inside. I haven't looked at this run yet, but I'm guessing it's the smaller size conduit. Just wondering if this was a common solution for this problem?
Thanks
Thanks