Different than mine but maybe some help.
The "flipper switch" would normally have a fixed on position and a spring loaded "demag cycle" on the other side.
The light would be on when chuck is powered, Blinking as the demag cycle runs.
I can't see if this is a motorized unit. On these the coils are switched back and forth by contacts as the current is reduced removing magnetism from your part.
Another wild guess but there should be a knob on a pot controlling full mag strength so you can back it down when you don't want the magnet to suck down and distort parts
This works wonders when your bottom side is not flat yet and even 1 1/2 square shanks bend on the chuck if you do not back off the power.
Then you flip them, they bend the other way. Mic perfect, under a tenth.....check like bannas on the surface plate.
That variable power makes electro chucks so much nicer than permanent mag ones
Neutrols or other such make the demag cycle way easier than flipping the polarity back and forth 20 times by hand or hand demaging which should be done to any standard steel part exposed to a magnetic chuck.
Bob