Abstract: An anti-theft alarm device for household items is disclosed. The device employs a motion sensor unit subject to magnetic control such that the alarm may be disabled, set to go off or reset after being sounded. The magnetic control is applied by a magnetic probe to a conductive ball sensor normally maintained on a nonconductive area between conducting surfaces of opposite polarity. When magnetic attraction is removed the ball is free to respond to motion and complete an alarm circuit. A mounting casing is provided, which may be used to mount the motion sensing unit and alarm circuit in a compact apparatus. Additional mounting hardware is provided to enable mounting the motion sensing unit on angulated or curved surfaces. The magnetic control functions may be set by radio control.