My light is wired incorrectly at the factory, earth is soldered to negative. And I'm having a bit of trouble with the sensor switches, a real switch is certainly more suitable at sea.
I bought three of these cabin lights for my J92s. I had an electrician fit them. Initially he found that he couldnt get them to work. Eventually (and at my expense for his hours of time) he discovered that the earth and neutral wires had been incorrectly soldered in the three units. These lights are not cheap, I would have expected better quality control from the manufacturer.