What does In the name of Mike mean?

"In the name of Mike" is a euphemism for "in the name of God" where that might be seen as impious or blasphemous (also synonymous with "what in the hell...?"). Prefacing a question with "what in the name of Mike" is an expression that may be querulous, exasperated, or incredulous. It may also mean that the person asking has no idea what the other person is trying to accomplish, or why it is being done.