I have a ceiling fan.
The logo on the pull cord of the switch says SMC

I need to replace the 2-wire switch that controls the light.

Where do I find the part?

John

Most all home stores will have a universal pull switch in the aisle with replacement blades and down rods. Take the old switch with you so you match it.

Very universal part available at any hardware store. Doesn't have to be an SMC part.

Ceiling fan pull chain replacement and repair - Ceiling Fans N More

The best way is to take the old one with you to your local Home Depot and match it because there's different types. Make a diagram of the wire connections so when you put the new one on you wire it the same way. And remember to always turn off power first. If you forget wich one is the hot, use a light tester to find the hot wire. Good luck.

There are actually NOT different types of two-wire pullchains.