scratching in walls pest control 4

https://post-wiki.win/index.php/Rodent_Proofing_Homes:_Practical_Steps_for_Long-Term_Protection

That scratching in the walls at night is probably a rodent, not a ghost. They can get in through tiny gaps and chew wires, so you'll want to find the entry point and set traps or call an expert. Sealing holes with steel wool is a good start.