I realized it was just the right size to fit in a bird box we had that was really the wrong size for any birds we're likely to get. DH took the front off of the box, and it will be a perfect fit.
Plus, DH cut and drilled more blocks to fill up the house (along with the nest-filled block) and extras. Think we'll add the shingles to the top of the little house and then use others to make a little roof for a condo of the extra blocks. We'll hang them in two different areas to see if we might still attract a few more nesters this year.
The drilled hole are 5/16 inch diameter and about 3 inches deep. We used untreated 2x4 boards we had in our misc. wood collection. We'll hang them where they are a little protected from the weather and have a morning sun exposure, but not the strong afternoon sun.
Thanks for sharing, Neighbor!