07 Chevy silverado brake light on cab staying on brake lights on rear bed work properly only cab light not going off unless pull up on brake pedal?

Brake Light Failure to Turn Off

Your question wording is a little confusing, but I suspect that the problem you're asking about is that the brake light does not turn OFF even though the the switch tests "good," meaning it is operating properly [opens and closes the electrical circuit when the plunger is depressed and extended/released].

IF the brake light switch is definitely good [working properly] then the most likely cause for the brake lights to remain turned on is that the position of the switch [the distance of the plunger tip from the brake pedal arm] is not adjusted properly.

Most mechanical type switches are adjusted by screwing the switch [which has a threaded mounting to a hole in the mounting bracket] either toward or away from the brake pedal arm [which depresses the switch plunger to turn off the brake lights].

It is immeasurably helpful to have an assistant stand behind the vehicle to observe and report the changes [on-off, etc.] as you make adjustments of the switch position. You should continue to make changes in the adjustment until the brake lights stay OFF when the brake pedal is not depressed, and the brake lights come on when the pedal is depressed.