This is a small, dark, confined wooden space with a divider that separates the priest taking the confession and the church goer.  There is a small seat on each side so that they can take their time discussing their sins.
Confessions room, Inside Church
worshipper
guard
I am a guard at the royal castle.  I am brave and strong.  It is my duty to protect the king.
I thought he was in the booth? Oh. Perhaps you are right. Hello father? are you in there? I'll try knocking, or maybe I can peek around the divider... Hmm, nothing. I say, this is quite odd. And I have such sins that need confessing! Woe is me. He is not there? No he's not... Maybe this is... God's plan? Am I not meant to disclose this deep dark secret burning a hole in my heart? Is this my penance, to live alone with naught but my dark deeds to keep my company? No solace? I rue the day this all first began. I cannot imagine what would have happened to him, I never saw him leave. Oh rue and woe! Have I truely been a blasphemer? God has abandoned me. My lot in life is to be unredeemed. I never knew such a small thing could set a man on the path to ruin. If I could only go back... I have such regret You seem to be overthinking this, maybe he just stepped out while I was distracted with something? Ohoh, so it all comes out. IT WAS YOU. You that neglected your duties. You that looked away at a crucial moment. You that let a fragile life wither on the vine.... Well perhaps not that last bit, but you have certainly failed in your sworn duty to protect the members of the clergy. He is a capable man in his own right, look he is returning from the bathroom as we speak. Gods providence is returned! Oh thank you kind guard. You truely kept my light alive in these dark times. I more just tried to keep you calm while you endlessly shouted... Such is the way of religion. if we weren't endlessly shouting, we might have time to examine the error of our way. And that is not for us to dwell on, but for the lord to judge.