How to wire a ceiling rose (the bulb flashes) (Ed.)

[FrodoOne]

SUNRAY has assumed that the Pull-Switch in the Bathroom controls the light that is
"directly outside bathroom and within 1 metre of this Pull Switch."

Is he correct, or am I correct in assuming that
the Pull-Switch controls the light in the Bathroom and
the flickering light "within 1 metre of this Pull Switch" is operated by another switch, elsewhere?

Thanks for all your help I will give it a go and get back to you, your illustration is very clear and much appreciated

However, you still have not commented on whether the "flickering"
is regular (pulsing)
or random (intermittent).

If the latter, it is likely to be a "loose connection" and, as I wrote in Post #13: -
"the Blue insulated conductor is the Neutral to the Ceiling Rose of the "flickering light"
connected to the Black insulated conductor in that Cable
via a screw-connecter
which probably IS the site of any loose connection!".

Have you checked the twin screw-connector?