Ghosting
Ghosting turns up in 2 fields: lighting, telecom & it. Here is what it means to the people in each one.
Ghosting in lighting
A faint glow from LED fixtures that are switched off, caused by small leakage currents in the wiring or controls.
Electronic switches, occupancy sensors and two-wire dimmers without a neutral pass a small current to power themselves, and long cable runs can couple voltage capacitively. Incandescent lamps ignored this, but efficient LEDs can glow dimly or flicker from it. Fixes include dimmers or sensors with a neutral connection, a load resistor across the fixture, or relocating switching to interrupt both conductors.
"Ghosting in the bedroom downlights at night, the smart switch has no neutral, add the bypass module at the first fixture."
Ghosting in telecom & it
A faint, offset duplicate of a television or display image caused by multipath interference or slow panel response.
Ghosting is a visual artifact where a secondary, fainter image appears slightly offset from the primary image on a screen. In analog broadcast television, it happens when the radio frequency signal bounces off buildings or terrain, arriving at the antenna slightly later than the direct signal. In digital displays, it refers to the visible trail left behind moving objects due to slow pixel response times.
"Adjust the Yagi antenna slightly to the left, we're still getting some ghosting on the VHF channels."