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.
Do not mix it up with
- Ghost light: A ghost light is a deliberate work light left on an empty stage; ghosting is an unwanted glow from switched-off LEDs.
Related terms
Pop-on
An LED dimming fault where fixtures stay off at low dimmer settings and then suddenly turn on at a higher level.
Driver
The electronic power supply that converts line voltage into the regulated current or voltage an LED needs.
Ghost light
A single bare lamp on a stand left burning center stage whenever a theater is dark and empty.