Is it safe to use a Magic Mouse with leaked batteries?

The white powder you found is likely potassium hydroxide, a substance commonly found in leaked alkaline batteries. It can be harmful if it comes into contact with your skin or eyes, so handling it with care is crucial. To be sure that the Magic Mouse will be safe to use:

• Wear gloves and possibly a mask while handling the affected area to avoid direct contact with the residue.
• Use a cotton swab or a soft cloth slightly dampened with a mixture of baking soda and water to neutralize any remaining residue.
• Check the battery compartment carefully for any corrosion on the battery leads or other components. If there is any significant corrosion on the leads which could affect their functionality.
• Ensure that the battery compartment is completely dry before inserting new batteries
• After cleaning and drying, insert new, fresh batteries and check if the mouse functions properly. If you notice any persistent issues or further signs of damage, it might be a good idea to replace the mouse. However, if the steps above are followed carefully, the mouse should be safe to use again.