This is one of Gracie's favorite tricks. She's about 20 inches high at the withers, just the size to reach a light switch here in the US.
Here's a video of Mum teaching Gracie to turn off the light switch using clicker training. Mum started with tape on the wall at a lower height for Gracie to target, then moved it up and up until the tape was right on the light switch.
Once Gracie got the hang of moving (flipping) the light switch, she removed the tape and started naming the behavior.