Oil Flicker

[Neox5]

I had a flickering oil light that would only show when the car was idle. When i would drive it would go away. I brought it to the stealer and they said that i needed a oil level switch. So i got it replaced........here is my issue.....the next day when i was stopped at a traffic light the oil light started to flicker again! I called up the stealer and they told me that sometimes when you replace a part something else also goes. Then the stealer asked me if a warm the truck up in the morning before i start driving? I thought to myself.....would that really make a difference???
They want me to bring the truck back in so they can look it over.

Any advice......thanks guys!