Thanks for the clarification.
You didn't mention the brand or model of your pump. That might help.
Ejector pump pressure switches I've seen are cylindrical and have a large horizontal surface on the bottom where the diaphragm is, like this:
From your picture, it looks like that box the cable runs to is somewhat slim. Maybe there's a diaphragm under it? I also see two cables, one looks like it's connected to the top of the pump (the feed?), the other runs from the box you identified as the switch and over the top of the pump, then out of the pit?
Whatever the case, your switch isn't working properly and rather than beating your head against the wall trying to figure out why, why not just buy an aftermarket float and bypass the existing switch.