I think I have one, although I think it came from something else than a PC. I'll check the P/N and report back.

EDIT: Markings read as follows: SOLTEAM PS3-22SP 10A250VAC TV-8. They're apparently available on the bay as well!

Thanks - I ordered a couple of those!

In an ironic twist of fate, I was tidying up some stuff today and I found I have one of these in a mixed spare parts box - it's in incredibly poor conditions so not viable for use, but the code is still readable: KDC-A04-10T100. That said, it looks like for these the code means very little - all the KDC-A04-10T100 I found on the 'net are actually latching, so the code itself means almost nothing.

To add some more info - this general type of switch seems to be mostly used in HEATING apparatus. Not sure exactly of what type, but they're only to be found on eBay or some specialized heating systems spare parts vendors. The likes of RSOnline, Mauser and so on don't seem to sell them.

Ahh non-latching old style for HVAC, like the switches used in some older natural gas furnaces behind the maintenance cover. If you pull cover it disconnects the hot 115v or 230v without having to kill at the breaker box....
my newer gas furnace has one but is more "rocker" style, if the mount was changed that would work just as well...just an thought.

You could always open it, if you're up for it. There's a little pin that rides in the groove on the shaft. Remove it and it will not latch anymore.