I've read the other questions on noises in wall but those were cominf from a bathroom this noise is in my children's bedroom wall and is like a vibrating noise it goes for 2 seconds stops goes for 3 sec stops over and over again had an electrician come out couldn't find anything its driving me insane there nothing on the other side of the wall that's the outside of the house

Could it be wood boring bees, they make a sound like you describe, they enter any expose wood even treated wood.