Yes, that's why I was confused. Do you mean "go" and "come" in the phrase in question stand for "turn"?Yes "over" and "above" and synonymous here. "On" is a preposition attached to "turn", we turn/switch televisions, lightbulbs, motors, "on" to get them working/started and turn/switch them "off" to stop them. So "a light bulb turned on" means "a light bulb was illuminated / lit itself up"
There are four expressions that are near-synonyms: come on, go on, switch on, turn on, all meaning "become energised". Their opposites are even more numerous: go off, switch off, turn off, go out, switch out, turn out, meaning "be extinguished". The choice between them often depends on the speaker's viewpoint and, as Entangledbank says, the human agency.Yes, that's why I was confused. Do you mean "go" and "come" in the phrase in question stand for "turn"?