@th while at it, it never hurts to check if the wires are really what their colors indicate.

@th You have junction boxes in your ceilings? My ceiling wiring just disappears into amorph caves.

@th at first glance it looks like the bare wire is blue, but that it is the same one going into a black wago with other black wires. Color change btw. blue and black is not good, or am I or the picture missing sth?

@th it's the surprise fun implement

@th it's extra in case you need to stretch the wire a little farther.

@th It’s a single-ended antenna! [1]

[1] A λ/lots antenna for a 50 Hz signal, obvs. Probably only effective in the near field regime.