Fuel safety switch won't stay depressed on its own, or start while holding it on 2004 Ford Explorer Sport Trac

Never had any fuel issues until now.
Ran fine yesterday, but no love this morning.
Cranks but won't fire. Safety switch won't click in.

Asked by for the 2004 Ford Explorer Sport Trac
Maybe that is not the problem!!
Yeah. That is what I'm trying to figure out. Just hoping to find out its something small, and not a total fuel pump replacement
Check for battery voltage at that switch, if present, pump is the next likely suspect.
Pump seems to be making a little noise, when I turn the key on. But its more of a weak squeak. Thanks for your prompt response, Pushrod. Going to check voltage now.
If you hear the pump running, fuel pressure needs to be checked.
Not sure how to do that. Walking to buy a teat light now.
I understand that but that is the next step in the diagnosis! Somehow, that has got to be done!!
OK thanks. Looking into it.