UK Light switches – My experiences (2020)

[JDRoberts]

@simont1952

If I put an earth wire into the N terminal, the switch becomes active

Earth (called “ground” in the US) and Neutral (the N port on that device) are NOT interchangeable. Remember that your goal is not merely to get that particular switch to turn on and off: it’s to get that particular switch to turn on and off without burning down your house or creating a shock hazard.

Sounds like it might be time to bring in an electrician.

FAQ: Neutral and Ground Wires are not Interchangeable

Continuing the discussion from Current Device Deals & Best Prices: They are both wires, but they serve very different purposes in a residential home circuit. One is grounded and one is grounding. If most of your experience has been with battery operated devices, or in a physics lab, you are generally working with direct-current, and,the ground and the neutral may well work in a very similar way. In these environments you do sometimes hear the statement that the ground and neutral are interchangeable. However, in a house, the ground will often be connected to a metal appliance such as a washing machine or a toaster, and normally carries very little current. Its purpose is to be used when there is a fault in the normal live circuit so that the extra current has someplace to go. The ne…

And here is a UK reference on the same topic:

APNT-23 - Understanding 2-wire and 3-wire Lighting Systems

It also sounds like you might need a different model of switch, one designed to work with two wire rather than three wire systems. But don’t connect earth to a neutral port, you will create a safety hazard.