Looking to make an electronic switch device for air horns. Essentially a plunger type similar to the ones for doors that indicate an open door or a momentary push button type. Want to put a chain on the one end securely mounted and the other on the switch itself. Should be normally open and closed only when the chain is pulled. Having trouble finding part numbers and stuff for the right type of switch to make this happen. Ideas, part numbers?

 

Looking for this item, this one is from the Cole Hersee catalog, but need to find a place that carries this or a similar item. Help a guy out!

 

just use a switch like the ones used for nitrous full trottle switches

 

like this one
http://cgi.ebay.com/10-pcs-Roller-Le...QQcmdZViewItem

 

Roller switch would be very awkward but may work in a pinch if I can't find a plunger style.