Keeping water out is **Really, really** hard, seriously the stuff is referred to as the "universal solvent" for a reason.
Just to give you a flavour of the failure modes...
Ok you have a cable coming in thru a waterproof gland, fine, but if the outer jacket of the cable gets damaged you will, sooner or later get water inside the box because it sneaks down between the jacket and the cores.
Single wire? Same thing happens, but it sneaks down between the conductors and the jacket.
PVC cable insulation.... Waterproof right? Well, not reliably so much as it turns out, we had a nightmare with this in a subsea application (Vendor had changed the composition without telling us).
Electrolysis is the big threat when you have wet electrics, not short circuit, it is amazing to see how quickly a power connector left power on in sea water will rot.
Personally I like overmoulded connections with PUR in that kind of environment, and even then you have to prepare the cable PUR jacket so it wets out properly with the compound.
From the sound of it, this is food prep area? The water may well contain bleach or other anti microbial compounds, treat it as salt water.
Regards, Dan.