[Clean and Repair your Mac keyboard: How-To Guide|http://lancej.blogspot.com/2008/04/clean-and-repair-your-mac-keyboard-how .html]
[Keyboard Repair|http://www.mactech.com:16080/articles/mactech/Vol.05/05.01/Keyboardrepai r/index.html]
[Apple Pro Keyboard repair|http://www.technology.niagarac.on.ca/people/bgracey/prokeyboardrepair.ht ml]
[Apple USB Keyboard (model M2452) repair|http://www.technology.niagarac.on.ca/people/bgracey/usbkeyboard/usbkeybo ard.html]
Is "wafer switch" something I can access and correct myself?
After reading all the above links? You can clean it, but if the switch is broken I doubt it is financially feasible.