I would suggest keeping the 6'(?) cord/plug on the compressor. You need to wire/conduit close to the compressor, install a box with the switch you choose, and then add a female outlet for the compressor's cord to plug into, I would add a pilot light of some fashion after the switch, it will have to be 240V wired between the two hot legs, or just use a single leg (120V), but that would require a neutral, do not be lulled into using the ground. Regardless, the compressor must have a proper ground. The post switch pilot light will help you not leaving the compressor on un attended. There are no stupid questions here, so ask, and safety first.