R.B.
I used to work for a sister company of Sunbeam (a huge maker of electric blankets), so we heard a LOT about them at work.
I have them and I used them. Because of the dangers of having the heat on too long, the blankets do now come with automatic shutoffs after a certain amount of time. So, that limits the issues of burning yourself or falling asleep and something happening.
As for where they are made, Sunbeam manufactures them themselves (not contract-manufactured by some other company that then sells them to Sunbeam). I know they have a huge blanket factory in Mexico, but as with nearly everything from computers to cells phones & toys, some electronic components are sourced from China or some other Asian country. Unfortunately, the U.S. just doesn't manufacture certain things anymore and we Americans aren't willing to pay the price at the cash register that it would take to make the stuff here. However, many of the final products of the Sunbeam blankets are assembled in the Sunbeam-owned factories in Mexico. They do have multiple factories in China, but I don't know if they make the blankets there. Most of their small kitchen appliances are done there.
NOTE: Sunbeam headquarters is in Florida and the parent company is out of New York, so at least the profits are staying in the U.S!