Around 1983 Vulcan Electronics Ltd made an electronic game called the XL 25. It could play two types of game. It played the standard Lights-Out game (although actually the aim was to switch all the lights on) and also a variant where each button changes its own light and those lights which are a chess knights move away.
The XL-25 was patented by David Ildiko, Laszlo Meroe, and Ferenc Szatmari, number WO83/02399, filed 16 January 1982, published 4 January 1983.
The Lights-Out variant need not be discussed further. The solution for the classic Lights Out can be used, except that on/off is swapped, i.e. when you chase lights you have to switch each row on instead of off. Below only the Knights Game is discussed.
Vulcan- XL25 (19??, LED, 4 AA Batteries, Model# ?)