How to Change a Light Switch II (Home Reno Tips)

Published on May 12, 2021

Part I is here.

Electrical work is once again my most hated during home renovation. In 2014, I wasn’t satisfied with the workers too.

While I understand it is probably not their responsibility to advise on light/switch/wiring compatibility, I took umbrage when they nagged me on my choice of light switches.

So in this video, I reveal their “trade secrets” 😄

Other questions you might have

Q: How to know which brown wire connects to what?

A: Use a test pen to deduce where the current flow IN first (bulb will light up). Then use that wire to touch others to find the light (the light will power on).


Q: Why are there 2 wires squeezed into “L” socket?

A: I covered this in Part I with diagram. One wire is for current in, the other is for current out. The current out connects to other room. If you don’t connect, the other room will not work (because they have no current in)!


Q: Why use Livolo?

A: It has RF remote controller. Super useful to turn off all lights in a room eg. when going to bed. It is also very cheap when they are on sale on Lazada (they moved to AliExpress).


Q: How smart switches can work without neutral?

A: Singapore switch box don’t have neutral, yet smart switch needs to be powered all the time (for the RF/Zigbee to work). The trick they use is to always close the circuit and let a small current runs to the light (where there is neutral wire that runs back to distribution box). It is small enough to power up the smart switch, yet not power up the light. This has complications.