This reminds me of a story about someone whose walls were being banged on loudly. They lived in an apartment complex so there was no supernatural angle to the story, just an ongoing dispute with the neighbor. They reported it to the landlord, called the police, but it never happened when people came to witness it. He was advised to make a recording to get proof. The noise was so obnoxious that it seemed like an obvious solution, so he gets an a little dedicated recorder and leaves it on his nightstand all day and all night, saving and clearing the files.

Two days in he has plenty of evidence and calls in the landlord. He plays back the recording and it only has the sounds of himself being pissed off, but no pounding. He himself no longer hears it now that someone else is present.

Long story short he got diagnosed with several serious medical conditions with side-effects including psychosis and hallucinations.

That's a scary story - but the lesson applies here, too. A recording can confirm or disprove the idea that the sounds you are hearing are real, physical sounds. If they are - check for rats, look around in the attic, etc. Real sounds can still be synchronicity and a real message from a spirit. If they're not, this doesn't rise to the level of medical emergency, but this moves them solidly into the realm of either spirit communication or your imagination. At least you'll know it isn't raccons. (If you have raccoons get help now, seriously)