MK 50A 1-Way Pull Cord Switch White with Neon (12094)

It depends on which sub-variant you were supplied with. This happened to me. But on reading, the small (very) print in the instructions state that the behaviour of the neon light depends upon whether the internal circuitry of the mechanism is type1 or type 2 configuration. Check this out first. Do not assume incorrect wiring. This is bad. That different configurations exist (or did exist) and which type you have should be stated boldly on the outer packaging and not hidden away inside the sealed packaging for discovery after opening.

If there is only 1 earth connection and you have two earth wires (presumably from the supply side and feed side) you should connect both earth wires to the marked earth connector otherwise you will not have earth continuity back to the mains board. Both wires should be sheathed with earth sheathing and not bare apart from at the connector. If your wire is bare you may be getting some interference that could be causing the faint red light to show

It does need a back box. I usually use a 47mm back box when I wire a shower in 10mm twin and earth as the cable is quite robust.

Good Morning, Thank you for your query. This model does indeed use a single earthing terminal arrangement. The earth terminal for the K3151 (which is the double pole version more suited to showers) can house: 4x 2.5mm , 2x 4.0mm or 1x 6mm cables. This is still complaint with the current British Standards; however, I will forward your comments to the product engineer who reviews the products regularly. Kind regards MK Technical