I'm sorry, I've had to remove this post as it's beyond the scope of our 20-year limit.

According to the 20th Amendment,

"Congress may by law provide for the case wherein neither a President elect nor a Vice President elect shall have qualified, declaring who shall then act as President, or the manner in which one who is to act shall be selected, and such person shall act accordingly until a President or Vice President shall have qualified."

Congress decides more or less.

Edit: this applies only to elections after 1932, as that's when the 20th Amendment was passed. You might be interested in the election of 1800, which took place under different election rules.

The government is more than just one person.