I have 2 Beolab 8000 that I am using as rear speakers to a BV7. I moved two months ago and now one of the speakers will turn itself on for a few seconds a few times a day. I can hear the power click and the green light comes on. A few seconds later it will go off.

Is this a cable problem or a loudspeaker problem?

Any ideas?

maybe try switching cables first to see if this is the problem...

Could be either a speaker problem or a problem with noise triggering the auto on of the speaker, which would I suppose be an environmental issue or cable.

Try swapping the speakers to see if the problem stays with that speaker or with that side of the room. Then perhaps try swapping cables, or running the speaker without cables and see if the same thing happens. You should be able to easily figure out whether it's the speaker or something external to it.