Product review (5 stars): right part for my Affinity Dryer (3rd - farthest heat sensor on the lower left (your left while facing the front) duct)
Did your Frigidaire Affinity Dryer throw an E66 code? Did your screen say open door or heater? Well, here it is, this baby is 1 of the possible 3 sensors for that code (farthest sensor on the bottom **your left** while facing the machine, just behind the 2nd sensor). I will give you the quick and dirty (but proper solution) solution if you want to read on. For those who don't, the part fits exactly and worked fine. My dryer is up and running.

For those who want to know how I figured it out:
to get the code, get your dry out of standby by twisting the knob or pressing the start. Immediately after hold start and cancel at the same time about 3 seconds. Write down the codes and anything else the screen may say. E66 states heater, but the unit still didn't register the door as being closed.

How to open your dryer:
- unplug it first!!
- 2 screws on the back hold the top panel. Opening that will give you access to the main control board (black or white control box on the top right of the drum). 137260140 Frigidaire Appliance Control Board - I found mine for cheap and my original board and some blackening on the relay so better safe than sorry, ordered a new on for about $100. Still 50% cheaper than what a repairman will sell it to you for. Trust me.
- On the front control panel (button controls), you only need to take off 2 screws, 1 on each side of that metal bracket connected to it. Nothing else, you can lift it away and set it on top of the drum without pulling plugs.

Then you can reach down and see the door trigger. Simply put pressure and push the door switch out front so you can multimeter test the metal tabs. The meter should give some reading if it working at all when switch is pressed and when released, the tester should read zero. If not swap probe contacts and try again. If not then there's on part you need to replace. (mine worked) To take apart the front simply remove the top 2 screws, the 2 behind the door (dont have to remove the door, just open it), and then 2 on the very bottom. Lift slightly up and pull out.

Second: do the same for the 3 thermal sensors. One is located behind the duct running from the front to back of the machine. It is a blind reach unless you really feel the need to take part more. I just lined up the probes with my index and middle finger tips and felt around for the metal contacts. Got a reading. Then on the left side, there is a smaller duct and you will see the next 2 sensors next to each other. I tested the 2nd closest to me, got a reading. 3rd is a little bit of a game of arm/hand twister but not bad (sorry, larger forearms will not squeeze past, you will have to remove the side panel to even test it or employ child labor - j/k haha ). Of course, I did not get a reading for the 3rd and farthest sensor. This is the part I am reviewing. You do have to remove the side panel unless you have a miracle trick to unscrew it in such a tight and awkward place.
***Note the markings on the old, don't think there's a right way to position the new on but I still put it word upright as the factory did on the original. Screw it back in and done!

Temporarily put back the front control board and plug back in. Test to see if the dryer will let you past the error code and start spinning the drum. If it does then Viola! permanently close it up.

UPDATE: 10/10/16 with baby #2 out, thank God I fixed this myself!! Been ripping through loads of laundry and it has been working spectacular. I hope everybody has the same luck.