Every day we touch the light switch, yet its success story in Switzerland, closely associated with the name Feller, is little known. The company Feller in Horgen has been significantly shaping the development of electrical engineering for over 100 years. In its specialty of switches and sockets, Feller soon held a near-monopoly position. After the early death of the founder Adolf Feller, his daughter Elisabeth Feller led the family business for decades, which at its peak employed over 1,000 men and women. Elisabeth Feller was not only active in the company but also strongly engaged in social, political, and cultural issues. Thanks to her, Feller became a pioneer in architecture and design. From the 1980s onwards, electronics were added to electromechanics, although Feller initially struggled with this transition.