Ford is recalling the charging cords for more than 50,000 plug-in hybrid and electric cars in North America, including 1,327 Canadian vehicles, because of a risk of fire.

Affected are the 2012-2015 model Ford Focus Electric, 2013-2015 Fusion Energi and 2013-15 C-Max Energi plug-in hybrids. Ford said owners will be notified next week by mail.

The 120-volt convenience charge cord originally provided with some of the vehicles can overheat an AC outlet that is not on a dedicated circuit or is damaged, causing a fire.

The company says it has reports of four fires but no injuries. In three of the fires, the owners were using extension cords, a practice Ford says is not recommended. It also recommends reading the manufacturer's instructions about the best kind of wall outlet to use.

Owners can take the cords to their dealers, who will replace them with ones equipped with a thermistor that can sense high temperatures and shut off charging if necessary.