[QUOTE=jr_tech;3152369]Would an arc fault detector outlet such as this add a degree of safety margin, if one is using an older electric blanket?

http://www.amazon.com/dp/B00AWJ8AV0/...ing=UTF8&psc=1

not affiliated,
AFCI breakers are required, per the NEC, for circuits that feed the bedrooms and a few of the other areas in the home.
It seems that they respond to arcs and poor connections, where heavy current is consumed. I'm not sure if they would respond to a fault in a lower power item, like an electric blanket. Having never owning one and not knowing what wattage they're rated at, is hard to say whether it would respond to a fault.