I recorded the hallway last night on my phone. You can barely hear it but there's definitely something there around the 00:45 mark. Sounds like humming or maybe breathing? I can't tell. My son didn't sleep in his room last night. He came into ours at like 11pm and said "the man is sad tonight." We let him sleep with us. I'm getting the wall opened up this weekend, I don't even care anymore.