Who was at the door trying to get into Nathan and Haley's house and leaving the doors open places in season 9? Did they ever say?

I don't think they ever said, but I just assumed it was Clay and his sleepwalking.

Dan? Because of episode 5 Season 9?

HALEY: Well? Answer the question, Dan. আপনি ব্যক্ত আপনি হারিয়ে গেছে everything in the fire, so why do আপনি have this? And all that money... why do আপনি have that? Was it not an accident? Did আপনি start the আগুন yourself? Oh, my God. আপনি did! আপনি started the fire! I trusted you. I let আপনি into my home. I defended you, and আপনি lied to me, and আপনি took advantage of me! And the doors... the doors here and at the cafe. Was that you, too?

DAN: Haley, will আপনি let me explain?

HALEY: What else are আপনি lying about, Dan? Where is Nathan? What did আপনি do to him?

It was Dan Scott, Nathan's dad.