After re-reading Posts #1 and Post #8, I suspect that
a. there
IS a light in the Bathroom
b. this light is controlled by the Pull-Switch
IN that bathroom
c. there is
another light OUTSIDE the bathroom
(within one meter of the pull switch - which is irrelevant), controlled by
another switch (
somewhere).
d. It is the light outside the Bathroom which "flickers".
e, The "flickering" started
after an "electricians" work on the Bathroom Pull-Switch
(and continues after MUNEEB's efforts)
f. There is 1 bedroom to the right and 1 bedroom to the left, supplied on the same circuit as the above two lights.
It has
not been explained if the "flicker" is "regular"
OR
if the "flicker" is intermittent - which may indicate a loose connection.
If the "flickering"
IS due to a loose connection in a
Line or Neutral conductor coming
from the Pull-Switch
to the Ceiling-Rose of the "flickering lamp",
it indicates that this lamp is at the "end of the circuit".
This is also indicated by
I have also checked behind the actual bulb wiring which looks fine 1 BLACK wire on left, 2 BLACK wires on right and 2 red wires in middle for loop.
although those numbers "Do Not Compute".
(Apart from the Earth, there MUST be an even number of conductors involved at any UK Ceiling Rose)
Line and Neutral IN, Line and "Switched" Line to/from the Switch
and
"Switched" Line and Neutral to the Luminaire itself - in this case.)
A
strong contender for any "Loose Connection" would be the screw connector connecting the BLUE (Neutral) wire,
which is shown in Picture 2 of Post #1.
There are
two cables coming in from the ceiling at the Pull Switch:-
Cable 1 (which
may be White) has Red, Black, Yellow and bare Earth conductors.
These will be the Line and Neutral coming in via the Bathroom Light Fitting
together with the Yellow "Switched" Line back to the Bathroom Light Fitting.
Cable 2 (Grey) has Red, Unknown (extended in Blue), Green (?!?!?) and bare Earth conductors.
(Unusual, to say the least !)
[While I really cannot imagine what function is performed by this "Green" insulated conductor (apart from an insulated "Earth" conductor) it does not appear to be in use.]
Fairly obviously, the Red insulated conductor is the Line to the Ceiling Rose of the "flickering light"
and
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!