The "Stinger" flashlight by the Streamlight brand has a brighter bulb than a conventional flashlight but is just as susceptible to a contact in the tail cap push button switch getting loose. This renders the flashlight unusable. To repair the switch, disassemble the tail cap and reseat the contact. A few tools common to most households will be needed, as will a special tool designed for use with tail caps.
Unscrew the tail cap from the back of the Stinger flashlight. Place the tail cap on a table with the open end facing up. Unscrew the ring from the top of the tail cap and place it aside. Insert the switch repair tool into the screw hole inside the cap. Twist the tool counterclockwise.
Push down on the tool to raise the insulator plate. Grip an edge of the insulator plate with the jaws of a set of needle-nose pliers. Pull the insulator plate out of the tail cap.
Grip the loose side contact pin that is inside the tail cap with the pliers. Pull the pin out. Reinsert the pin into the side of the insulator plate. Return the insulator plate into the tail cap. Insert the tool into the screw hole in the tail cap. Twist the tool clockwise. Screw the ring back onto the top of the tail cap.