Abstract: A switch (10) comprises a face plate (16) and a single switch sensing oscillator (18) responsive to a switch activating presence. The oscillator (18) has a resistive component (36) connected to a sensing plate (38) which acts as a first capacitor plate. The face plate (16) is arranged to prevent electrical contact between the user and the oscillator (18). Any object, when placed adjacent the face plate (16), acts as a second capacitor plate which alters the frequency of the oscillator (18). A microprocessor (20) senses the smoke detector (62). In a further aspect the switch includes a mains electricity cable signal transmitter/receiver and a microprocessor whereby each such switch may communicate directly with another such switch.

Abstract: An underground prospecting method and apparatus that utilizes the harmonics and fractional harmonic waves induced into the earth by the electric power grid. The data are converted to amplitude-depth and phase-depth data. The resulting data may be plotted and are compared to known patterns of the interested underground features, such as hydrocarbon, water, minerals and cavities, to identify whether the features exist and at what depth such underground features lie.

Abstract: A switch (10) comprises a face plate (16) and a single switch sensing oscillator (18) responsive to a switch activating presence. The oscillator (18) has a resistive component (36) connected to a sensing plate (38) which acts as a first capacitor plate. The face plate (16) is arranged to prevent electrical contact between the user and the oscillator (18). Any object, when placed adjacent the face plate (16), acts as a second capacitor plate which alters the frequency of the oscillator (18). A microprocessor (20) senses the change in frequency and activates the switch (10) in response to the change. In another aspect a mains light switch (10) includes a smoke detector (62). In a further aspect the switch includes a means electricity cable signal transmitter/receiver and a microprocessor whereby each such switch may communicate directly with another such switch.