Strange problem with voltage / light

Hi everyone,

we bought a 110-year-old semi-detached house. It is really still in great condition, even though we of course had to do quite a bit of renovation.

I have a strange problem with a lamp cable. When we moved in, there was a lamp hanging in the hallway that worked perfectly. A normal 230V incandescent bulb. During the renovation, we removed all the lamps and replaced them. This lamp here was off for several weeks.

When we wanted to reconnect it, we found out that there is only 12V there now and therefore the lamp no longer works. At the associated light switch, there are even only 6V.

I can't explain what caused this. We are completely puzzled. The only electrical work I did nearby was to clip off the doorbell cable because we have a digital doorbell (Ring) with battery. But that can't be related, can it?

I know that remote diagnosis is really difficult. But maybe someone has a tip for me. If not, I might have the possibility to connect something to the 12V?

Best regards and thanks
Marius

I would get a measuring device and measure it. Or ask your electrician. It shouldn’t cost much. There are 12V lights, but I wouldn’t connect anything there. There is a fault somewhere and in the worst case, your house could burn down if suddenly 230V comes through.

You did not drill any holes?

That can definitely be related to the doorbell. When I read 6V/12V, I immediately thought of the doorbell transformer. Either measure through and get to the bottom of it. If you are not a professional, please have an electrician take a look.

What year is the entire electrical system from?

At how many points can the lamp in the hallway be switched on (how many light switches are there for this)?