Abstract: A contact unit for applying current to a person's skin through an electrically conductive casting composition spread over an area of skin to be treated for therapeutical or beauty purposes. The contact unit electrically interconnects an electric current generator lead and the casting composition and comprises a flexible conductive plate made of an elastomer containing a conductive powder and in contact with the conductive core of the lead. An insulating liner overlies a first face of the plate and extends along the edge thereof and terminates flush with the second or uncovered face of the plate. The insulating liner bears against a first layer of the casting composition in contact with the person's skin. A second layer of the casting composition overlies the first layer and the second or uncovered face of the plate. Thus the electric current from the contact unit cannot flow directly through the first layer to the subjacent skin area so as to avoid burning the skin.