Check the metal. The problem is probably that the toggle has disconnected from the circuit terminals.

Melted Wires Parking Lights And Dash Lights Wont Turn Off
Light wont turn off after wiring. If it does youve found the problem. Try gently wiggling the switch to see if this causes a flicker. I am trying to install a new light fixturebut the light does not turn off when switched offthe fixture has two blackstwo whites and one ground wirethe ceiling box has two white two black one red i am assuming the red on the ceiling box is groundi connected all the whites together. A wire getting loose in a terminal screw or in a wire connector at the switch or light fixture could cause the flicker. The circuit for the light fixture should be turned off so these items may be inspected and apply the repairs as needed. Check to see if the bulb is tight in the socket.
3 if you have only 1 wire instead. If so replace the bulb. Loose wiring connection in the light fixture. Discover how to troubleshoot light switches and light switch wiring with these how to videos on on off switch switch plates light switches light switch electrical wiring wiring light switch. Light will not turn off using light switch 1 some electrical outlets have metal tabs on the side that connect the upper and lower receptacles. Check the light bulb first to see if it has burned out.
If your light is already flickering try toggling the switch on and off and see if this fixes the problem. If the light bulb does not light up at all follow this troubleshooting procedure. Moisture inside the light fixture or detector head. If you find the light switch wont turn off immediately after youve installed it its probably because you wired it wrong but if the switch has been working and suddenly you find the light stays on when the switch is off the switch is malfunctioning. A poor connection between the light or fixture switch and the bulb can cause flickering. A corroded contactor inside the switch could cause the flicker but would also probably cause the switch to feel warm at the touch.
The constant on off flow of electricity can sometimes loosen a light. 2 you would want to be fairly certain the outlet has little metal tabs that connect top and bottom on each side. I hope this helps dave.