Aphelion

The story reminded me a bit of the recent Doctor Who episode in which millions of mysterious black cubes appear all over the world -- and do nothing for months, until people accept them and take them into their homes. I asked the author (if I recall correctly) what the triggering mechanism might be for the devices NOT in the basement workshops of part-time inventors -- surely not everybody would rig a microwave source and aim it at the device...

Kind of a fun story, but the dialog wasn't very good, not very natural sounding. Should have had more contractions.

And we never got to find out what the HW/WM marking meant. Maybe the author is saving that for a sequel.

I forgot to mention earlier, but it seemed to me that all the characters in the story had the same personality, too. They were all perky, cheerful, hard-working, good folks. I think there's a chance that the author did this intentionally, though.