Although the spelling "employe" is not as common as "employee", it is apparently in widespread use to some degree: employe - Google Search=. I didn't know that until I checked. I don't feel that we should necessarily dismiss online resources as being less reliable than print resources. One must exercise caution when using online reference material, but one could say the same thing about printed material. Here's an example: 50 Years of Stupid Grammar Advice - The Chronicle Review - The Chronicle of Higher Education
By the way, Google usually asks "Did you mean *******?" when you mispell a word, or it thinks you mispelled a word. That did not happen when I typed "employe". I think we should conclude that this spelling exists, is used, and is correct.