I found a new touch panel (or membrane switch pad) for < $166 at http://www.myapplianceparts.com/ . The person on the phone at this company was very pleasant and immediatley confirmed that they had 10 of these in stock. This suggests to me that more than a few of these have gone bad. Luckily, they are very simple to replace if you are willing to turn a few screws and carefully pull of the electrical connectors. I dissasembled mine in 20 minutes, got the part number (#62682B for my ECS130), and found best price in 20 minutes.
I have usually seen 2 problems causing the light to come on and off. 1: the door hinges have been sligtly bent and need to be replaced (the door doesn't push the light switch all the way in and the light can come on and off) or 2: The touch pad on these tend to go bad and make intermittent connections for no apparent reason. This is called the membrane switch. It is mounted to the front panel from behind, and you will have to remove the erc you installed to get it out. I belive this mebrane switch pad is much cheaper than the erc, but I'm not sure of that. The touch pad is also miore likely to cause other problems, wheras the hinge problem is only going to cause the light to come on sometimes. Hope this helps!
Usually answered in minutes!