This hangar is made specifically for the Calibre 6 blade razor from Aldi pictured here but it will fit many and could be modified to fit most.
A single fixing screw holds the base plate to the wall and the outer part fits tight and is held fast with a stainless steel grub screw or two on the under side. I use only one in my installation and it is rock solid.
Middle hole at the bottom is for internal drainage of any moisture and should not have a grub screw installed.
The razor drops into a tight lock and can only be removed by gently lifting it around 20mm, otherwise it is held tight!