I have a 3 speed 4wire exaust fan motor and am looking for a 3 position switch for same, all the switches I have found are just 2 wire switches... I need a 4 wire switch for same to fit a single gang switch box. 120 v

If you have the original old switch, take it to an electronic supply store and check at the "City Desk" to see if they have a replacement switch.

Also, check the web and see if you can find the manufacturer of the fan and then visit their web site to see if they have a customer support line available for you to contact.

Look Very close for numbers on them, There are a couple of different switching arraingments.
Scroll down through this page:
http://www.ceiling-fans-n-more.com/ceiling-fan-pullchain-replacement-and-repair.php
Zing Ear is commonly used:
http://www.zingear.com/Templates/En/ProductList.aspx?typeid=34