This is a small box, suitable for Chickadees or House Wrens. Yep the entrance has been pecked at.
I heard the cheeps for two days each time I passed by. Today I was busy with errands and other things and had not gotten a chance to go out in the garden until recently. So I just checked. I got a powerful flash light and opened up the back of the nest box and looked in. One baby. No others and no other eggs, The nest is soft and totally liked with feathers. The chick is quite small. Someone must be feeding it.