In my entire life I have only seen one very strange thing. It occurred a few years ago as I was eating my evening meal after work. Something on the ceiling caught my eye. I turned and looked straight at it. It was small, domed, about 5 inches in length. It had a vaguely organic appearance (a bit like a trilobite) but perhaps technological and extremely old. I stared at it for about two seconds, when it started to shimmer slightly, fading until it was gone. It was although some field to make it non visible had malfunctioned then been reset. I picked up a chair and ran my hand over the ceiling where it had been, but nothing. To be clear, I looked right at it for several seconds, I was about six feet away, there is no possibility it was anything other than I describe. It has not happened again. The house is not particularly old, about fifty years. I have attached an image, it is the actual room with my drawing of it added. Perhaps describing it here may enable someone with a similar experience to collaborate.