Trying to swap out an existing pool light switch with a new LED light w/ inclusive switch. The old switch was a standard toggle switch, 3 wires (meaning the outlet is wired white, black, ground) . The new "fancy" switch has 4 wires coming from it.... One in, one out, one neutral and one ground. There is a transformer between the light and switch.

The installer eventually got it working but I'm curious how it should be wired, given the scenario. I just want to make sure it's done right.

I appreciate any feedback.


The right way is that there was a neutral wire in the switch box (likely for newer houses, unlikely for older ones) and that was connected to the switch. It’s ok if there was multiple neutral wires, all connected together, in which case, the switch would be connected to the entire bundle.

The wrong way would have been to use ground as neutral. This would be illegal and potentially dangerous.

Given that a pool is involved, which could increase the danger, I applaud you checking into this.

  • The house is wired with 3 wires. Are you saying that I should have a 4th wire run? I'm confused over why the newer switch /controller has 4 wires.... There's always been a transformer between the switch and pool light (before the LED). Unfortunately, to make it work, it was connected wire in, wire out and the neutral and ground were connected to ground. – missusm Apr 9 at 13:42
  • Well, that's a codevio and you need to rip it out. "But it works this way" You need to rip it out. I presume this guy was a handyman and not an electrician. – Harper Apr 10 at 0:43
  • Your new, “fancy” switch needs a connection to neutral to work. You don’t have a neutral,available so your contractor used the ground instead. The ground and neutral tie together back at the main panel so it works. The problem is that the ground connects locally to various metal parts exposed to be touched. If the ground wire back fails the now isolated local ground could be carrying 120 volts (through the switch) and potentially electrocute someone! You really need to either get a true neutral wire to the box or change to a switch that doesn’t need a neutral. – DoxyLover Apr 10 at 6:14
  • If you have conduit to this box, you may be able to get a neutral wire pulled through. – DoxyLover Apr 10 at 6:14

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