Soft glowing light, flaring, dimming irregularly.I routinely step out at night and scan my sky with binoculars. I live in an active aviation corridor between the coast and Orlando Int Airport, so there is always something flying overhead and I also enjoy spotting stars and planets.Tonite, I stepped out just in time to observe an unusual light travelling south to north. It is quite muggy here, but I had very good viewing conditions, and the sky was relatively dark, as a storm front moving in from the west was blocking light pollution from the Orlando direction.This anomalous light seemed to be at a high altitude , appearing like commercial passenger jet traffic. What really got my attention as unusual was the fluctuations of this light. It was a single source of soft, off white nondescript light. It was a single light source not resembling navigation lighting, and it appeared to be glowing. Its size, though, was about what you might expect had it been an airplane at 30,000 ft. Its intensity varied irregularly and greatly as it travelled rather quickly across the sky. I have seen satellites pass over before, usually as a steady faint light, and twice in a regular sort of flashing, indicating rotation or tumble. That's what I figured I had here at first. But this thing flared , ebbed, waivered and flared in such an irregular pattern,and with irregular intensities. Without ever going completely dark. It was almost spooky. I immediately ran for my tablet and checked the app "Heavens Above" however, it did not indicate the passi! ng of any satellite in this path and heading or even time slot. The steady speed and straight flight would seem to indicate satellite, but I have NEVER seen such a strange light display. It leaves me excited and confounded! I'm not so sure this was any satellite. I don't know WHAT I saw.