Do I need a Neutral Wire for In-Wall Devices? April 03, 2019 16:11 Updated Follow Yes. Due to the power requirements of Wi-Fi technology a neutral wire is required. If you need assistance determining if you have a neutral, consult the Wiring section or view this video. Related articles How do I know if I have a Neutral? Video - How to Identify a Neutral Wire Can I Connect the Neutral Terminal (marked WH) to Ground? How to Identify a Neutral Wire What bulb types do Decora Smart Z-Wave dimmers support?