I am a complete DIY novice, and reading through past posts mean nothing to me, so I'm desperate for some very basic advice!!!
Our upstairs hall light can be controlled by a switch upstairs and downstairs, however we could only control the downstairs hall light downstairs. I'm hoping we will be able to do both from both upstairs and downstairs so I bought a double switch from Homebase. See pic of back. It's a bit dark (I've turned off the electricity!) but there are two holes that say COM and then two that are L1 and two L2.
I've also attached a picture of the wires coming out the wall. There are two red, a yellow and a black. All have brown tape wrapped around them OTHER than the two red wires.
I can see a yellow/green wire has been attached to the back of the box, and then disappears into the plaster (I'm not sure if this is bad plastering or meant to happen!?)
What colour wire goes into which of the COM, L1 or L2?