Smart switch 1 gang 1 way

[Tandoori]

Hi, i’ve been trying to buy a smart switch 1 gang 1 way but i opened my conventional wall switch and i only have 1 red wire(Live Old UK) 1 black wire(Neutral Old UK) and 1 Green/Yellow(Earth Old UK) but the smart switches have another wire the Load wire, now i’m confused how does this work?

 

[SJD]

The black wire is a switched live (L). There is no N at this switch - which is pretty common way of wiring, especially for older houses.

 

[Tandoori]

The black wire is a switched live (L). There is no N at this switch - which is pretty common way of wiring, especially for older houses.

So would a “No neutral required” smart switch work in replacing the existing switch? Also thank you for explaining this, i had been confused the whole day

 

[Avo Mk8]

Yes - buy a smart switch that does not require a neutral.
To work they require a small current to flow through the light fitting all the time. With filament bulbs this is no problem, but with some LED bulbs this can lead to the bulb glowing dimly, or flashing. The workaround is fitting a capacitor/snubber across the bulb, and I believe some no-neutral smart switches provide this component along with their switch.
So it is possible to fit a smart switch, but it's a little more hassle than when you have a neutral (which, as said above, most people in older houses do not have!)