First post so be gentle with me!
Our modern house has two external lights - one by the front door, the other by the garage.
The light by the front door is controlled by a switch in the hall, which the previous owner replaced with a central heaing control, simply so he could use the timer.
I have taken this off, and see two cables, each with red live wires, black neutral and yellow/green earth which are fixed in the earth terminal of the box.
I bought a 6AX intermediate switch (maybe wrongly) and wired up per diagrams - each red and black cable in individual holes (L1-L4)
Having done that the outside light is on permanently.
I didn't know at the time, but I beleive that the two sets of wires relate to each outside light, as I noticed the sensor controlled garage light came on at the same time.
Any thoughts please? - have I perhaps bought the wrong lightswitch?
The controller I removed had the 2 neutrals together but the lights tripped when I tried that.