No, microwaves will not damage your food if they are turned on but not plugged into an electrical outlet. When a microwave oven is not plugged in, it does not generate microwaves, and therefore, it cannot heat or cook the food.
Microwaves work by producing electromagnetic waves that excite water molecules in food, causing them to vibrate and generate heat. When the microwave is not connected to a power source, it cannot produce these microwaves, so there is no risk of damaging your food or causing any cooking effects.
However, it's important to handle any electrical appliance, including microwaves, with caution. Always ensure that your microwave is properly plugged into a functioning electrical outlet when in use. Also, keep it away from water and avoid using it if there are any visible signs of damage or malfunction.