Seeing the previous thread on wireless light switches reminded me of
this link which might prove useful and save someone some money.

http://www.amazon.co.uk/product-reviews/B001CFJA6M - Second review

I had bought a three set of these and found you had to wander round the
room to make them function, which rather defeated the whole idea. Having
followed the suggested procedure, they now work brilliantly. Why theyr
are sent out untuned I have no idea, bit obviously the QC stickers are
meaningless.

Obviously take note of the dire warnings regarding electricity being
DANGEROUS.

Andy C