From the manufacturer's info I've seen on two such products, they are most adamant that the product be GFI protected - even away from the shower.
There are also numerous megger tests made at different points during the installation.
So ... checking the manufacturer's instructions would be the place to start. They might even advise against use in the shower at all.
These are generally custom products, ordered for specific jobs. Yet, I'm beginning to see the topic pop up on DIY forums, as folks try to modify, adapt, and hillbilly-engineer the things. I say: DON'T do it.