Yeah run right out and buy another part.
Could be loose wire.
Could be the fuse link that is weak.
Could be the nut behind the wheel is loose.
Look at the switch, start the car let it run a while, at least three songs on a Rolling Stones CD, slightly move the key switch around and wiggle the connector at the switch.
Most times there are burnt connections and melted plastic so it maybe visible, Ford did a recall or TSB on it.
I've replaced mine twice, I'm surprised this was not mentioned before, classic symptom.