Every time I switch on one specific circuit breaker, the residual-current device (RCD) switches off. I've disconnected every device that's on the group, and even took out all light bulbs, but the problem doesn't go away.
I think there are two options now, either there's something wrong with the circuit breaker, or with the wiring (there are three other groups that share the RCD, but I have no problem with those, so I think the RCD is OK).
Are there other options, and how do I find out where my problem is?
(I know next to nothing about electrical wiring, so I hope I got the terms right.)