Rogue One

I had some new security lights installed.  Of course, the one that is not behaving itself (and won't switch off) is the only one that I don't have a ladder tall enough to reach myself, and which I have to go into the attic just to switch off.

It was installed yesterday, didn't shut off, replaced today, still didn't shut off.  Not sure if it's a faulty batch, or something has gone wrong with the installation...

Further (doubtless tedious) investigation required...