Why a green coloured bulb is dimming after switch offmy nikon d60?

A green coloured bulb near the lcd screen in the rear side is dimming after switch off ny Nikon d60.so please tell me why this is happening.

Old.

It's powering down. There's no point in it staying on when you turn off the camera.

It's showing the SD memory card activity. When you turn power off, it unmounts the SD card so you can remove it. All this is telling you is do not remove the memory card when the light is flashing after you turn the camera off.

If you looked at your camera manual on page 5, you'll see item 11 which leads you to page 23.