A switch is a thin, flexible twig from a tree or shrub used as an implement in corporal punishment. The application of a switch is called switching.
Switch in Adam Johann Braun's Maedchenschule, 1789
L'Exécution de la Punition de Fouet by Jean Baptiste Debret
Birching is a form of corporal punishment with a birch rod, typically used to strike the recipient's bare buttocks, although occasionally the back and/or shoulders.
Switch (corporal punishment)
…Caning Birching Corporal punishment in the home…
Birching of a prison inmate during interrogation; The Netherlands, 17th century
A magistrate's committal for birching of two children dated 4 December 1899 displayed in West Midlands Police Museum, Sparkhill, Birmingham, England
Birching in a women's prison, US (c. 1890)
1839 caricature by George Cruikshank of a school flogging