We hear this very faint noise, sounds static like or if a small wire were being scratched against something. It is at least 1 foot above a horizontal line where the outlets are and about 4ft away from the nearest outlet so we don't think it is electrical. There is nothing on the other side of the wall just the vaulted ceiling from below. The house is 23 years old so not much settling going on at this point. Not sure if it could be termites, we live in Colorado. Any thoughts?

Are any of the outlets in use when you hear this sound?
If not, does using any of the outlets stop or change the sound?