I recently bought a house in norwood, oh and I was adding a new light fixture. Upon cutting a hole to fish the wires thru, I stumbled upon a circular metal piece that is covering about 45% of a stud. I was wondering if anyone could shed some light on this object. the house was built in the 1940's, and the plaster was/is in bad shape. I can email a picture. but cant upload it to computer.