In mystery crime stories of old any death in households with servants, whether suspicious or not, its ALWAYS the Butler wot done it!

Also, there used to be machines at seaside amusement arcades with 'rude flick images of ladies undressing' (or what the folk in the 1920s considered rude, anyway). There was a little peep-hole to look through.

These machines were called 'what the butler saw' !