1995 Mazda Millenia Sticky Starter

I have an old 1995 Mazda Millenia with 156K miles. Over the last couple of weeks the ignition has become very sticky, to the point that many times I think it is stuck. The only way I can get the car to switch on is to vigorously shake the steering wheel while trying to turn the key. ANy ideas?

The ignition lock or switch is worn out and needs to be replaced. I think the former. Does it start every time you can turn the key? Try a locksmith.