Aldi have had a pack of 3 on sale recently and they may still be in some stores, like many such mechanical switches they use a ring of rotating segments which work a switch in a cam action with the on position set by pushing the segments inwards
Purchased a pack and today did a dry run on a LED light string purchased last year in a closing down sale. They run from a USB plug and as the only USB power supply capable of suppling the 9 watts required I had to hand was a 12 Watt I Pad one I used that. Plugged in at 1600 with the segments for that time depressed in the on position and through to 23.00.
At 23.30 I noticed the lights were still on and went to investigate. Found the clearance from the segments in their raised off position was so tight they fouled on the apex of the charger and so stopped the dial turning. It is now running again but slightly noisy , it will end up in the shed so no problem.
Just thought I?d mention it in case anyone else has purchased a set and don?t notice how close the dial is to the socket part, I expect a few similar power supplies or wall warts may foul the dial as well.
GH