Key spins
 

I got in my 2000 996 and found the ignition key would spin freely and not start the car. The radio and idiot lights turned on when I initially rotated the key and then the key went limp and spun freely. After some research on this forum I figured the electrical portion of the ignition switch had failed. I picked up a switch and went to replace it. After removing the lower duct I could see the switch but it looked firmly attached to the mechanical portion which was not what I had expected. I then stuck the key in with one hand while holding the electrical portion from under the dash. I thought I might detect the failure mode. Instead, the key now worked normally and everything function tests ok. Do any of you guys have any idea what happened? I am worried about it stranding me some day.

There are two small set screws that hold in the electrical part of the switch. I would go through the process of replacing the electrical switch and making sure the set screws are tight.

Replace the part you bought. Make sure you tighten the set screws. Several how-to on here, and also on Pelican site.