a slightly easier and cheaper way would be to go to one of the big box stores or your local hardware store/electrical supply house and buy a short extension cord, some wire nuts, metal handy box, and a switch. Cut the extension cord and wire the switch in line. You would wire nut the white and green wires straight thru, basically green to green and white to white so they are passing thru like the cord had never been cut and wire the black or red (hot) wire thru the switch. Or you could do this to your pump cord if you dont care about cutting it up. People in the electrical departments should be able to help you out. I would probably go the extension cord route. I wouldn't pay an electrician unless you are completely not a diy person.
