Where do the french put relays?

[more_confused]

As a novice forum user I initially posted in the wrong place, my original post was:

I'm living in France and I have a single hall light which is controlled by 3 rocker switches (not sure if that is the right term but they always spring back to their original position), or it was. Now the light stays illuminated permanently regardless of what I do with the switches. I've tried the switches on a different circuit and they all work. A colleague says this sounds like a relay problem.

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securespark replied:
Your lighting system uses a relay, with multi-position momentary ptm (push-to-make) switches (hence the spring-loaded action) As far as I'm aware, the relay/system is known as "auto-alimentation".
It looks likely that the relay has energised to turn the light on, and got stuck.
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Now can anyone suggest where I might find the relay? In the fuse box or somewhere in the circuitry or somewhere completely different?

Thanks