In article ,
F news@nowhere wrote:
It looks as though I'm going to have to thread a thin, so very flexible,
cable into the ceiling void from below and then out again a couple of
metres further across. I've used a straightened coat hanger in similar
circumstances before but the current stock won't straighten to the
required distance.

I can't get at it from above, but at least the joists run in the right
direction for me.

So what's the best way to do it?

feed an extending metal tape measure through the space at the other end,
tie on a piece of string and then retract the tape, pulling the string
through. Remove string from tape and fix to cable. Then pull string from
far end.

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from KT24 in Surrey, England