Box Enclosure Case - recommendation

[Jane]

Can anyone suggest a material for a Box Enclosure Case  for my DIY project?
The project will use 220V.

I was thinking about a plastic box but when searching for a such box I came across a  seller  that says  plastic box
not being safe for those 220V.
Can anyone explain please?
Do you use plastic or aluminium or different material for your projects

[Macbeth]

Of course plastic is safe. With a metal enclosure you have to make sure you have a good earth connection to the case with shake proof washers and the like. If this is going into production then there are standards to follow I have to admit I don't know, but there is no reason you can't have a plastic case for mains equipment. I would say the opposite in fact!

How do they get away with cheap "wall-warts"?

[retrolefty]

Plastic enclosure are available for such service, however be aware that if multiple conduit penetrations are made that the conduits must be connected together with wire jumpers inside the box to maintain electrical grounding of the external conduits.