I originally planned to wait and see if these really work but, this challenge came up so, maybe other members want to try it also.
You can buy these professionally made but, I just used scrap pine. Height about 5 3/4", Width about 4". 1/4" dowels abt 1 1/2" and
mesh material to put cotton, dog hair, twine or other materials a Hummingbird can use to start a nest.
I used the easy way out and just cut one side of the roof 3/4" longer than the other side to over-lap but, it could be miter cut.