A candle snuffer was typically used to extinguish candles, lanterns, and other small flames. It is well within the capabilities of Mage Hand provided that the action is within the range requirements, so it could carry one of these over to snuff out such a flame.
Mage Hand (paraphrased):
You can carry an object up to 10 lb. As an action you can move the hand a distance of 30 ft. each time you cast it, provided it stays within 30 ft of you.
A similar item on a larger scale could be used on torches and stay within the 10 lb limit.
A gallon of water weighs about 8 lb., so putting out a campfire is pushing the limits of Mage Hand. Although it could separate the logs, it may take more than one casting to carry enough water to put out a fire.