Sven, Is it one I sent you attached to a string of 240V Christmas lights?
They were obsolete when I arrived in South Africa in 1982 but were still available in hardware stores and might still be. They were only ever used to plug into adaptors like the one below – I never came across two pin outlets in the walls but I wonder if early adaptors allowed them to be plugged into a lighting fixture which in the earliest homes were often the only source of power in a room.
The plug Sven is talking about is the one on the left. On the right is a Schuko plug which fits the same holes. Let’s just say the one on the right is to illustrate the hole size and spacing as it has previously been pointed out that I have put a class one plug in a class two hole! Just shows how important it is to develop a fail-safe design!
That adaptor is now used more commonly to accept two pin Europlugs that seem to appear on all imported class two equipment in South Africa. This Europlug adaptor design has been superseded by one that incorporates the six-sided raised shield that envelops the Europlug and prevents me from plugging in either of the two variants illustrated above.