Why does the fuel pump on my ford f 150 keep running after I turn the truck off?

I have a 1990 ford f 150. When I turn off the truck, my fuel pump continues to run. I also have a problem with the ignition lock cylinder. Could the cylinder be a part of the problem with the fuel pump?Why does the fuel pump on my ford f 150 keep running after I turn the truck off?Yes, ofcourse.