There isn't much doubt about it. People came to Arizona because of the mining opportunities. Gold, silver and copper were the natural resources that eventually led to Arizona becoming a state. Prospectors left California, came to the Arizona territory and brought with them the people who would support the mining efforts--the people of mining towns. Ghost towns aren't necessarily spooky or haunted by spirits, evil or otherwise. Philip Varney, in his book Arizona Ghost Towns and Mining Camps
defines a ghost town as having "two characteristics: the population has decreased markedly, and the initial reason (such as a mine or a railroad) no longer keeps people in the community."
Here are some details and links about the more interesting Ghost Towns that are within about 100 miles of the Phoenix area. They are all day trips from the Phoenix area, although you may want to spend some more time at a few of them. Some of them are open to the public. Still, today, there are people looking for lost treasures associated with some of these mines.
Links to the Ghost Towns
The Vulture Mine