Had power going to ground.

Will the engine turnover?

No wont do anything, check battery has voltage, dome light and door chime would come on briefly when he would jiggle or move the key switch.

You said he replaced the wireing,may i ask why,this may help me know your issue.

Do you mean you found cut wires in the ignition circuit, and not ignition (spark,plug) wires? GM uses a purple wire to energize the starter circuit. Was it cut? This might have been a circuit cut for an after market anti theft device that was removed (did you remove it or have a friend do it?). Eit her way, "lose and jiggly" is usually a complaint oF the ignition lock cylinder and not the actual ignition switch. The switch mechanism is usually on top of the steering column inside what I cal a "vault" that hands cannot enter because it's so small, shielded, hard to reach and designed to give some security to it, no matter how good McGovern is on TV at stealing cars by grabbing some wires under "there". The mechanical part - rack gear, tumbler mechanism, relay rod and/or some pot metal component has broken or become elongated. If you've got airbags in that column, BE YE VERY CAREFUL or you can get your head removed. Anything in YELLOW is a keep away warning under the dash or inside the steering column.

PS: I hate spell checkers. Sorry for it causing the typos.