Coming at this literature from the angle of
an existing musical setting by a specific composer, as I did,
takes the words out of context;
and if one is as ignorant as I, one misses most all of it!

John Bowden has put us on the right track. In fact,
the "Hütchen" is mentioned -- along with name variations --
in the Fairy Mythology of Thomas Keightley.
If your edition of Keightley has two volumes, then
the place to look is Volume Two, under Germany,
in the category "Kobolds."