So the little bugger darling came into our bedroom this morning, handed me the PEC and said, don't touch the light. He totally understands what it means, he just doesn't care.
Indigo - Its not the noise I think, its the fact that the light goes on and he can see to play/read/annoy DS2. He doesn't turn it on and off IYSWIM, it just stays on. I'm going to try to get hold of some epsom salts this afternoon to see if that helps him calm down.
Tape might work, at least for long enough for him to get bored and give up
Thought about turning the fuse off but we wouldn't have the monitor if we did that and that is a problem because we can't trust him and we can't hear them from downstairs (bedroom is a long way away and our house is pretty well sound proofed).
Rewards have to be instant for him to "get it", and at the time of the night, he is not going to get chocolate/DS/Wii or whatever he wants, it would only happen the next morning and that's too long for him to understand.
moosemama - I will do some more searching and see if I can find a UK source, they are good ideas, thanks.
Keep the suggestions coming. Fortunately (for me) I'm out tonight so DH has got to deal with it and we've got a birthday party in a couple of hours so he's going to be very wound up....