There is a useful difference between detecting a signal and identifying its source. A microphone records changing pressure. A recording can be real, repeatable, and still leave the cause uncertain.
Think of three separate questions: Is there a measurable event? Can we describe it consistently? What produced it? Answering the first does not automatically answer the third.
For an investigation, write down a specific claim before testing it. “A short sound occurs when this door moves” is easier to examine than “the room feels active.” Repeat the condition, change one factor, and preserve attempts where nothing happens.
This is an editorial guide to evidence language, not a report of a new scientific discovery. Unexplained is a statement about current knowledge. It is not the name of an explanation.