no neutral wire in lighting circuit - is this dangerous?

[ProDave]

Thanks, just to confirm, the single core runs from the light fitting to the landing switch which is 2 way and can be switched on/off downstairs, from what's been posted on here it sounds like it's safe, thanks again

Quite likely that is the L to the landing light, it may get it's neutral from another circuit. That was quite a common fault.

 

[unphased]

Domestic electrical wiring comes in many guises and as long as you know what you are doing you can wire things up in several ways. 6181Y is single insulated and sheathed, no cpc. Can be purchased in all sizes, most common sizes are 16mm2 and 25mm2 for meter tails. 1.0mm2 and 1.5mm2 is useful for lighting circuits (brown or blue). 6241y, single and cpc, is also still used, as pointed out on previous posts in the thread, in brown and blue variants, and then the most commonly used 6242y 'twin and earth' cable in brown/blue or twin brown with a single cpc. 6243y, 3-core and cpc (usually brown/black/grey), also popular when wiring timer fans and for two-way lighting switches. Good electricians sleeve the grey and black with appropriate colour to denote neutral and switched live. cpc should always be sleeved green/yellow, often omitted by DiY'ers

PS: I've deliberately avoided mentioning commercial and industrial wiring because they use all sorts including flex, swa, split concentric 4-core 5 core, SY, YY Cy etc.