I thought this would interesting - Our Old House Sharing

medicine cabinets or on walls, was a razor blade disposal slot if your blade got dull, you just put it in the slot, no need to worry about

Old medicine cabinets include a small slot in the back for old razor blades We found these blades when Dad removed the old cabinet

old casino slot machines 1940s medicine cabinets had razor blade disposal slots RonSchott before disposable razors people would pop the old razors behind the mirror

old slot cars so where do all those used razor blades go? in the bottom of the wall! and they wait there until some poor future remodeler decides to