There is no reason the fuel pump should be running when the key is turned off and out of the ignition. You can look under the hood in the fuse and relay box for the fuel pump relay. Pull it and see if your noise goes away. If it does put it back ans ee if it starts again. If it does I would remove it until you are ready to start it up in teh morning and go to the Dealer and have them fix it. If it is a 04 it should be under warranty still unless you drive the hell out of it.