Discouraging house sparrows the passive way.
House sparrows in your area will often try to stake claim to a nest box even if they can't get into it. This makes it difficult to successfully attract migrants such as swallows or other urban birds such as chickadees or bewick's wren. One passive method that seems to selectively discourage house sparrows that has worked for me is to mount reflective streamers near the box and have the wind blow them around.
For my swallow box, I used a few flashy barbie bicycle handlebar streamers and stapled them to the roof soffit. These blow and dangle around the box and the house sparrows don't hang around. The nesting chickadees (our substitutes swallows last year) were not bothered by the streamers and they successfully fledged their brood.
Here's a commercially available sparrow spooker as an example but the concept is just to have something blowing and dangling above the box: https://www.sparrowtraps.net/sparrow-spookers/
For the house sparrows themselves, I find I am not too concerned with them being successful in finding an alternate nest box location. So long as big box stores continue to sell the cheap birdbox kits, the house sparrow species will continue to successfully multiply.