I am replacing both of the hallway light switches in my house in the UK, and upon taking off the old switches, I am met with the following cable configuration:
Downstairs is a 2-gang switch that controls both the downstairs hall light, and the upstairs hall light. I know which wires control the downstairs light and can successfully wire it in.
Upstairs, there are 2 sets of 3 wires coming in, one with a red sleeve on the black wire, and one with the black wire disconnected and covered with electrical tape.
Inside the back box of the switch downstairs, there was also an extra piece of brown cable, but I don't know what it was connected to.
How should I connect these wires to a 2-way switch for the upstairs light?