But we're not here to help people hurt themselves, either. Sometimes the question itself, belies such a lack of familiarity with the basic issues, that the best advice is "you shouldn't DIY that particular project".
You have to know your limits.
Example: I can spec out the beams for this renovation I'm planning, as far as the dead & live loads go. But as far as figuring out the shear loads, and designing the moment frame connections to handle it, I'm much better off just calling an engineer.
The poster's asking about plugging a 110 appliance into a 220 receptacle... best answer is: "you shouldn't be messing with electricity". Anything else would be irresponsible on our part.