I live in a block of apartments with 6 floors having a stairwell timer that lights all bulbs of the floors at once. I would like to make my bulb switch on independently from the timer so that I can install a motion sensor which would only light my bulb. When I opened the wall socket that is used to light the bulb (and the others) which is a push button switch similar to that used for doorbells, I found a red wire connected to one of the terminals which seems to have continuous electricity supply and two brown wires joined together and connected to the other terminal. The neutral is wired directly in the light bulb holder. I disconnected the two joined brown wires to run some tests and found out that one of these wires is connected to the bulb however, I cannot understand why this wire has electricity when there is no bulb in the holder. Can someone help me out on how to go about this please? thanks
I suggest that you don't have the right to interfere with communal wiring and lighting, one because it is not part of your property (leased, rented or owned) and two, because you may not have the qualifications or insurance coverage to do that work.
However, If you want a light for your door controlled by a motion detector then there are LED lights with batteries available to do what you need.