Blinking light in the sky over Grand Rapids, witnessed from Wyoming, MI, watched it move back and forth and then suddenly to the west (I have a video on my digital infrared binoculurs). Called control tower at Grand Rapids Airport who said they didn't see anything on their radar. Called Wyoming Police Department who said they did not know of any Police Helicopter activity going on (Including Michigan State Police, which did do helicopter training the previous night.) But there was no sound and this definitely did NOT move like a Helicopter!