Dreaming of turning on the power supply indicates that the efforts you have put in will suddenly be rewarded, or the good things you have done long ago will suddenly receive unexpected rewards.
Dreaming of cutting off the power supply may indicate a decline in health or confidence, and depression of emotions.
Dreaming of a sudden power outage suggests that you may encounter an accident.
Dreaming of an electric shock suggests that you may receive news that surprises you.