These were sold by Carrier Corp. from January 2002 to December 2006 and they have had five reports of the electric heater failing and causing fires that were thankfully contained to the units themselves.
The approximately 185,000 units model numbers involved in this recall can be found in
this pdf file as their are quite a few different model numbers to cover in this particular recall.
To be on the safe side check it out if you happened to purchase a Carrier brand terminal air conditioner and packaged terminal heat pump during the time frame of January 2002 to December 2006 at prices ranging from $425 to $675.
Now this is a lot of units to be floating about so if you do happen to be the owner of one of them make sure you see about the free repair you are entitled to through Carrier (800) 761-8492 between 8 a.m. and 6 p.m. ET Monday through Friday, or the web site
here.