I have had to replace the switch on my Sears Craftsman radial arm saw several times. I use a pushbutton single pole, single throw (SPST) switch from Radio Shack. It is stock number 275-671. The retail price is $ 5.99 US plus sales tax.
(The red rectangle is a label with my name. To be cautious about Internet security I made it illegible for this photo.)
This Instructable applies to Sears radial arm saws that look like this one (The photo is from an earlier Instructable.) This series of saws was made from the late 1940's through the early 1970's. My saw was made in 1972.