Why does my stud finder detect electrical wires over a large area of my wall?
Here is an easy method to determine the location of live wires, with a stud finder. I have a stud finder on which there is no means to adjust the sensitivity of the live wire detector. However, you may use paper for the same purpose. Stud finder is sensitive to the electric field; electric field depends on the distance (i.e. how far you are from the live wire) and the medium (i.e. the material between you and wire (air or other material). If you put some paper between the stud finder and the wall you decrease the sensitivity of the stud finder. I use phone book pages for this purpose (they are free and you may add as many pages as needed). The thickness of the pages may go from one page to 1 centimeter or more depending on the current in the wire, and the paint used on the wall. You will see that the stud finder sounds for electricity only when it comes on top of the wire; you can pinpoint the location of the wire exactly. I hope this info helps someone. Good luck.