Of course, there is a web site for "as seen on TV", so, of course, I spent some of my not very valuable time searching for the gadget that I "must have". (See "I need this gadget" below) I think I've found it, although it is not the kind of gadget I previously sort of believed I was looking for. There are, of course, hundreds of gadgets - useful and mostly not so much - on this web site of little known treasures for one's consideration.
I thought for awhile the gadget I had been taken with might have been the BBQ food thermometer, but have now pretty much discarded that idea. Possibly it was one of the handy little drain cleaning devices, but they really don't have the obsession factor I held for this mystery gadget. Then there were the Flexfit lids, which would certainly be useful to have, but I was quite sure they were not what I would think of as "a gadget". I also discarded the idea that I needed Bender Balls for better abs, an automatic shoe polisher, a boot and glove dryer or a hands free blow dryer, among other things.
I finally settled on the Smart Light at $30 plus an exorbitant shipping charge. This 4 in 1 gadget turns on and off at dusk and dawn, becomes a flashlight if needed and pops on when you walk by it to light up the path in front of me, which occasionally in my house might include a spot of pee. (That's dog pee, not a misprint for tea). This is more likely to be at the bottom of the stairs in the morning. Since I leave a night light on for my one-eyed Princess, this would have caught my attention, as I sometimes forget - the night light, not the Princess.
I have concluded I will be able to live comfortably for the foreseeable future without the newly identified gadget, and I definitely won't miss most of the other gadget purchase opportunities. Ah! What a relief to have this mystery solved. And cheaply too, costing only about an hour of my not at all precious time.