[Tweeters] Bewick's Wren roosting behavior?

[Shelf Life Community Story Project via Tweeters]

Every evening, a Bewick’s Wren sits on the fence making all kinds of noise, just before dusk turns to night, and then it disappears into the bird block on the outside of the garage attic. Bird block is wood 2x4 sections with holes drilled for ventilation and steel mesh covering the holes to, not surprisingly, block birds from entering the attic. There is a tiny ledge in each hole before the steel mesh. It is less than an inch of ledge. This is definitely not enough space for even a wren to have built a nest. Could this wren just be using that tiny space as a place to spend the night? I’ve never seen this behavior before. 

Jill
Seattle