"Dave Plowman" wrote ...

By that definition there is no such thing as a "wireless mic"! :-)

I'd say most would consider an all in one design like a radio
hand mic to be just that. Some are no bigger than near equivalent
corded types. And a high quality stereo version that could be
'slung' for say classical recordings would find many applications -
if you could provide reasonable battery life.

And I doubt the OP would be interested at that price. ;-)

The OP didn't state a budget, or much of anything for that matter.

You have to read between the lines on these sorts of question. ;-)

You didn't have to read between the lines to see that the OP
explicitly asked for something "roughly the size/shape of ear-bud
headphones, or maybe a little larger." In my book this precludes
any kind of "radio hand mic".