Once upon a time, there was a difference between on and off. Now, it’s more complicated: Roughly 50 devices and appliances in the typical American household are always drawing power, even when they appear to be off, estimates Alan Meier, a senior scientist at the Department of Energy’s Berkeley Lab.

https://www.nytimes.com/2016/05/08/science/just-how-much-power-do-your-electronics-use-when-they-are-off.html