Why Do Some Old Houses Have Slits in the Medicine Cabinet?

Some of these slots are simply cut into the wall or medicine cabinet, but others were made decorative through the use of special blade slot tiles Blade bank

I live in a late 40's apartment building in LA with the original medicine cabinet intact and it has a slot for razors ( first time I have ever

medicine cabinet razor blade slot razor blade slot , electrical outlet and side mirrors The accessories shall meet the fol- lowing requirements , as applicable Electrical

medicine cabinet with razor blade slot 112 Miniature Retro Medicine Cabinet Items - band aids, aspirin