The Tio ghost concept comes from designer Tim Holley. The idea is to teach kids the value of conserving electricity in a fun way.
The switch will stay green whenever it has been left on for an hour or less, and the longer it is left switched on, the more the color will gradually change to yellow, until you end up with an angry red ghost. This might be a great way to teach them about time as well. Who knows, we may see this move beyond the conceptual stage and bore kids for real with learning stuff.