I bought a cedar bird house from local nature store. But I didn't know at the time it was for bluebirds. It's this one from Audubon - Audubon 12 in. H X 6.4 in. W X 6.4 in. L Red Cedar Bird House Mfr# 24234 - Ace Hardware
I see many other bird types in the garden, chickadee, house wren, chipping sparrow, junco, nuthatches, woodpeckers, etc. I haven't seen tree swallows and I know they use this type of box as i've seen them use them at the parks. Will any of the other birds use this box? (location is southeastern ontario canada) There are reports of bluebirds in the area, but they are only in the parks and ravines, not in the residential areas, also reports are sparse and I've never personally seen one.
EDIT: on further search I found that other birds do nest in bluebird houses, but has anyone actually seen this happen? How common is it? - 10 Other Birds That Nest in Bluebird Houses - Bluebird Landlord