Product review (5 stars): Right Part.
If your research into the part you need led you here this is probably the part for you. However if you have a little WD40 you may not need this part. What happens is that over time debris collects at this switch and hinders full movement. Usually the machine will either refuse to start a cycle or otherwise complete all cycles, all because of this little switch. It is a magnetic switch so bypassing is tricky and I won't address that here. Without even opening the machine, get some WD40 all over this switch that you can get to, work the switch back and forth and keep spraying with that stuff! Then try the machine, it sometimes helps to give the door a little slam just to shock that switch into sliding into place properly. If this seems to fix your issue then it was the switch that you need to replace and not the mother board or some such part.
My advice would be to go ahead and buy one and replace the old one, although you kinda fixed it the problem will keep coming back. As others have stated, there are enough YouTube videos out there to help you to get this installed and the machine calibrated.