Capacitive detection using a luminescent gas in the detection circuit is used to simultaneously detect and display an image of an object hidden behind an obscuring surface. The gas tube and electrode are arranged so that the gas tube may be rotated under the electrode to scan a larger area. The illumination provided by the gas is based on the level of capacitance detected as the gas tube rotates. The shape of a hidden object is visually displayed by the gas. In another arrangement, an electrode pad is rotated and has a light indicator device, such as an array of LEDs, co-located at the rotating electrode which receives the level of capacitance detected by the rotating electrode. The electrode and co-located visual displays are rotated at the persistence-of-vision rate of a user so a continuous display results.