Newbie here so hope you don't mind me crashing straight in with a query.
I have an interesting but infuriating and worrying problem.
I am quite conversant with electrics so the task of replacing existing florries with downlights didn't phase me.
I made the circuit up and left the last connection untill I had isolated the power (As you would) I live in a 1960's chalet which has had an extension added and the prev occupant also had a circuit installed to the garage.
I flicked the fuse switch on the downstairs lights and to be safe, the garage AND upstairs lights leaving just the mains live.
Picked up the switched supply 1.5 T&E and cut it to the required length using (Fortunately insulated) wire cutters, and this tripped the fuse box?
Ok, great, I thought. Some dimwit has taken the lighting for this room from the mains.
Completed the connection anyway to check that it'd work and no problems.
Not believing someone could be THAT stupid I decided to check to find out if, throwing the mains switch would extinguish the lights. Nope!
Tried the various fuse switches and the only one that switched the supply to the upstairs lights is the fuse for the upstairs lights.
Now, I THOUGHT I understood electrics but this one has me baffled.
The one thing that I did note was that the T&E used is the old colours but still grey PVC sheathing. It MAY be that someone used the old wiring (DIY).