I just spent $40 on eBay for a fancy billet kill switch that I can't even use because when it came I checked it, and it works the same as a stock switch. Its normally open, and closes when you hold the button in.
http://www.ebay.com/itm/221049469469?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
http://www.ebay.com/itm/221049469469?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649