This switch is a common failure item and Jet will send you another under warranty (5 year warranty). The switch actually fails internally, it is not just saw dust. You can find a replacement locally also, or plug the lathe into a power strip (using it as a temporary switching device) until you get the replacement in.
The switch is a multi part switch... the actual contact is made when you flip the switch lever and it moves a little "rocker" arm from one contact to an open contact... it's really simple to pull the switch out, open it up and make sure the rocker hasn't slipped out of it's pivots... a couple of years back I though I had a motor problem with my 1014... called Jet and bought another motor... when I put it in, I pulled the switch and discovered the rocker had done just that... probably didn't need the motor.
I have the same problem with my table saw... it uses the same type of switch... about every 3-6 months I have to pull it out, clean out the sawdust and reset the rocker into the pivot points.
Baring that, contact a local electrical outlet and show them the switch they can probably match it with a new one that will work... I had to do that with my dust collector... that switch actually shorted out and burned the contacts to the point I had to replace it... just got one from the local electrical outlet and was back up and running in a day.
First advice from SteveG is right on though... Jet's warranty is pretty good and they will get a switch to you in about a week.