I went to look over the newly-bought house of a young relative today (first time buyer, North East London suburb). At the back of the house I found this large grey plastic box outside fixed to the wall just above some decking. It does not appear to be linked to the double socket to its left, which has its own MCB in the consumer unit. It may or may not be linked to an external switch which is not shown but which is above the junction box to the left of the twin socket. It was raining Datsun cogs and I didn't want to unscrew the cover to investigate further. There is no outside lighting or other electrical device and no sign of there having been any. However there is a 6A MCB in the consumer unit labelled "garden lighting point". The small square in the middle of the unit's front cover is not a logo. Does anyone have any idea what the unit might be ?