I'm with Neale on this one - but anyway, we haven't yet actually been helpful about your original question.

I don't think you need a separate 5V PSU to achieve this - it looks like you've got 5V and Gnd available from the breakout board, and as its a signal line it won't be drawing a large current to worry about. I'm sure a more electronicsy person can chime in and confirm or deny.

The switches also are quite overkill - I wouldn't expect the illumination to work on 5V DC at these currents as its designed for 240V AC, so you might be able to find yourself something simpler. End of the day though, they're switches so will function.

Should be as simple as ENABLE - wired directly to GND, and +5V via switch to ENABLE+. Hopefully one of those electronics boffins will tell you if you need a pull-down resistor or not. You may need to tell the drive that you want to use the ENABLE signal, most of them ignore it by default so that people can leave them disconnected. Your stepper driver manual should give some details on this.