Manufacturing guy-at-large.
In 2012 I was assigned to design, test and prototype a custom faceplate for a high end Lutron light switch. The client was building a contemporary minimalist summer home, and wanted his light switches to be installed such that they were barely visible in his Venetian plaster walls. The assembly I designed used magnetic 400-series stainless steel pins and neodymium magnets to allow a temporary screed guide to be swapped out for the permanent cover plate after plaster installation, and included a tool to be used for that purpose.