Hi, Problem with downstairs light not working, has worked for years previously just stopped working one day , have no live feed to switch or light connections so I'm guessing that we must have a junction box somewhere & radial wiring so a loose connection in a junction box? I have checked the continuity from the red out wire to the lamp and it's OK. 3 wires run into the light red, black & earth. I have traced the switch 2 black neutral wires with a toner 1 goes to the CH thermostat the other goes in the same direction but stops short of the thermostat, when the 2 black wires are separated the thermostat stops working. How do I locate the junction box if there is one to minimise the work to rectify if behind plaster wall or ceiling, are wire detectors any good? Thanks appreciate any help I'm stumped. Photo 1 of light switch. Photo 2 of kitchen light switch in the next room.