I have installed a Decorator Switch by Cooper Wiring Devices. The light on the switch flashes, any idea why?

Either you have a defective switch or you did not connect the switch properly.

Can you tell us what connections were made when you installed the switch.

The pilot light is many wall switches will only work properly when controlling certain loads, such as an incandescent lamp, but not with a compact fluorescent lamp.

What is switch controlling?