A wire hidden inside a wall carries a current. How will yoiu find wire is horizontal or verlical?

As we know that two parallel current carrying wires exerts force on each other, attractive when they have current in same direction and repulsive when they will have current in different directions. Therefore first of all suspend a small current carrying wire in front of that wall, if the wire being attracted or repulsed by the wall then the wire inside it is horizontal and if not then it is vertically placed. Hope......you find it helpful....