I’m considering on buying a Xiaomi smart wall switch but I had to consider the neutral or no neutral switch which led to me opening my wall switch to check. Which got me even confused...

My wall switch

May I know how do I determine which wires are which (live, neutral, earth) and why are there 2 wires connected together?

  • It looks like you just have the "Line" wire, I don't see a neutral or ground. Is this light controlled by more than one switch? This question would probably be better on home improvement.SE.
    – Ron Beyer
    Nov 29, 2019 at 17:08
  • Light switches are normally wired such that the neutral, switched live and earth go to the lamp, the switch has just a live and a switched live (and earth). No neutral.
    – Jason Morgan
    Nov 29, 2019 at 17:12
  • Can you post a photo that looks into the back of the box please? Nov 30, 2019 at 1:25

2 Answers 2


Don't hook stuff like this to mains wiring. This product is not listed by BSI, TUV, CSA, UL or any reputable testing lab. As such it may not be legal to install.

A quick peruse of the brand says that they don't even bother faking a CE stamp, CE being not a testing lab at all, but a mere promise of self-certification, that is meaningless unless the seller is a bricks-and-mortar manufacturer or importer with substantial physical presence in the EU. If Siemens builds it in Germany, CE means something. If Siemens imports it to their warehouse in Rotterdam and then ships pallets to Wickes, then CE means something because Siemens is the importer. Anything having to do with Alibaba, Banggood, eBay, or Amazon Marketplace, they are doing that to evade safety regs: you're the importer.

So no, leave those products behind, unless they run on batteries.



simulate this circuit – Schematic created using CircuitLab

Figure 1. Your switch has no neutral and no earth, just a live loop and a wire to the load.

  • Even though there is no need for a neutral or ground connection to the switch, those wires may be in the box.
    – Charles Cowie
    Nov 29, 2019 at 17:28

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