The answer to 'cricket scratching sounds' is that they are likely caused by crickets or other insects making noise inside your home. Crickets often find their way indoors and can make scratching, chirping, or clicking sounds, especially at night. This is their way of communicating and can be quite loud and disruptive.
The most common causes of cricket sounds indoors are that they have found a way to get into your home, perhaps through cracks or openings, and are looking for food, water, or a place to nest. You may also hear them if they are trapped somewhere like behind walls or in attics.