I have a energy saving spiral light bulb in my kitchen. In exactly every 27 seconds, the first segment of the bulb faintly flashes when the switch is off. And not once, repeatedly every 27 seconds. This weird situation occurs for more than half and a year. What can be causing these flashes? How can I prevent it if it spends energy or has safety risks?
PS: A new spiral bulb does the same thing. And the bulb doesn't flash when I remove from socket.