We all have at least one 9 volt battery in our homes. They can be almost anywhere.
When we need to replace one, there is something we need to realize - both terminals of the battery are very close together and can be shorted out by anything metal. If they
are shorted, even an old depleted battery contains enough energy to become very hot and possibly start a fire.
The video below describes what can happen and how to SAFELY dispose of these batteries.