Installing a MS-OPS2 with no neutral or ground wire available

[Brightidea]

Hello,

Inside of my light switch box, I see that conduit tubes is used with one red and one blue wire coming out of it. There is no white neutral or bare cooper wire inside either. I live in a post war apartment building.

I was told by an electrician that the junction box itself could act as a ground. But inside the wall cavity where the junction box lies, it is solid concrete as there's no soft spots such as a wood beam or drywall to attach a screw with the neutral and ground wires from the MS-OPS2 attached to it.

Any suggestions or tips on how to get around this?

Thanks.

[Kyle L.]

Hello. Before you go and perform the work to install a ground screw in your box, have you verified with a multimeter that you get 120V between your hot wire and the box? This must be the case if you want the MS-OPS2 to work in this application.