I think you need an appropriately shaped and sized mounting block behind the fixture.

I did not think this was appropriate. This may be for an electrical plug.

The metal strap is going to block any electrical outlet and is designed to hang a light. But I don't think anything in that photo is for use outside. I've seen interior wall plates like that used for a recessed outlet behind a wall clock.

-- amateur

I appreciate you help.

Oh my.

YES this is right, the block is there so you can mount to a flat surface. As to not fight the ridges the siding creates. The only problem with this style is you not have to make sure the backplate fits into that area.

The work is sloppy yes, and perhaps this was not the right style to choose but the principle is correct..

My concern is actually pooling water, how did they mount it is it sealed so water does not run behind and into the electrical box..