My MakerFront i3Pro did not come with a power switch and was designed to be hard wired to the AC plug. I found a rocker switch and built a box to put it in. I was not going to build the box big enough to put my fingers in to unlatch the self locking mechanism on the switch so I had to build it flush to the switch so that there was nothing to engage it, in case I ever wanted to remove it. The box has an overhang to mount to the left z motor and fits flush against it. Run the wires through the box and slide the box down the wires as far as you can, attach the wires, and push the switch into the box.

Customize this in OpenScad (free). Export to STL. Slice in your favorite slicer (Slic3r). Send g-code to printer.