Yes — and it’s more common than you’d think.
A 9-volt battery has both terminals on the same side, close together. If you toss a loose one into a drawer with paper clips, coins, or other metal objects, the battery can short-circuit. That creates heat. Enough heat to ignite paper, fabric, or whatever is nearby.
Fire departments have documented cases where a single 9-volt in a junk drawer started a house fire. The battery didn’t need to be connected to anything. It just needed to touch the wrong thing at the wrong time.
The fix is simple: store 9-volts in their original packaging, or cover the terminals with tape before throwing them in a drawer. It’s a two-second habit that can prevent a disaster.
So yes, that tiny battery can burn your house down. Respect the voltage.