Did you break your oath after someone extinguished the light switch before you, and then you made him turn it on again so you could extinguish it?

If by your oath you intended to turn off the light due to discomfort, then you have not broken your oath if someone else turned it off; because the intention was achieved and the intention is what counts. However, if you intended to do it yourself, then you have broken your oath and expiation is required of you. And if the oath was uttered by your tongue unintentionally, it is considered a laghw (idle oath) for which there is no accountability, based on the Almighty’s saying: "Allah will not impose blame upon you for what is unintentional in your oaths."