Having checked the link, it appears not suitable for Corsa*, rather Astra. I wasn't aware there was a difference but looking at the picture on the sale it seems to be a coarser pitch M10 thread?
You need the M10 x 1.0mm which is for a Corsa (and others), I think this one should be correct;
http://www.ebay.co.uk/itm/Vauxhall-A...19.m1438.l2649 but would advise asking or checking before ordering
* The switch I had that fits Ducati fitted a 2005 Corsa 1.2