They neglected to mention that you might BURN YOUR HOUSE DOWN while charging your electric roller skate.
You must be referencing the two instances where a Chevy Volt happened to be parked in a garage when a fire started.
The first was in Barkhamsted, Connecticut in April 2011. The fire marshal concluded that the fire was started by a nearby Suzuki Samurai that the owner had converted to an electric car in a do-it-yourself conversion.
The second was in Mooresville, North Carolina in November 2011. The fire marshal there concluded, once again, that the fire started elsewhere in the garage and not in the Volt.
Other than those, there have been no reports of this happening.