DIY advice - neutral wire cut on supply to lights

Hi, I’m new to the forum. Thanks for letting me join. Asking for some diy advicd…

I’m trying to add a couple more security lights to the existing circuit but stumped at two things -

- The wires travel from the switch, to the existing security lights, then loop back (creating extra cable) to then travel up the house and into the loft. I disconnected the wire traveling up into the loft to see if this cut out a circuit upstairs but it didn’t, just the security lights had lost power. I’m assuming the supply feeds down from the loft, direct into the light and then loops back round into the switch. Question - how would I rewire this so there is only one cable supplying the security lights from the switch?

- From the switch, the supply to the lights has the neutral wire cut and just left in the back box bare. This doesn’t seem safe. Question - is there a reason why this has been left like this?

I’ve added a couple of pictures to help explain.

Cheers!

It's actually all a bit academic as the grey twin and earth cable shouldn't be being used outside (not UV rated) so really the whole lot needs doing again from scratch, and it sounds like it would start with a joint box in the loft to connect some new suitable cable.

What are you wanting with the switching - as security lights normally stay powered all the time. They just need a suitable means of isolation somewhere, which doesn't have to be the existing switch.

To answer one of your questions, the cable without the black connected is taking a switched live from the left hand light switch (left when back on the wall) to whatever it feeds. Is that the security lights or something else?

It really all needs testing, dismantling, and reinstalled using the right cable.