Should I check inside the nesting box ?

I have a sparrow that sits outside the nesting box chirping all day long it sometimes looks into the box through the hole but never goes inside. It sits in the hedge above and on the wall beside the box, it seems distressed like it wants to go in the box but can’t? No other birds go in or come out of the box. It’s been going on daily for a few weeks now, is this normal bird behaviour ?