The option of rotary switch or pull chain is available on select fixtures. Not all fixtures will have the option to have a switch due to the parts used to assemble the fixtures.
The rotary switch will be a small knob located on the base of the fixture that can be twisted to turn the fixture on. The switch will match the finish of the fixture you purchase.
The pull-chain will be located on the base of the fixture, and will include 6 inches of beaded chain with a decorative grip on the end of the chain. The finish will match the fixture you purchase.
We've compiled a list of lights that are compatible with switches. You can find sconces with the option available here or surface mounts here.