oil light on/flickering!?

I just got my oil changed in my '72 valiant and now the oil light is on and at times flickering..im puzzled..what could it be? got me worried.
If you did not have this problem before the oil was changed, then ask yourself what is different since then. Answer: oil and filter.

Assuming they put oil in it, which I am since you did not say it blew up, I would second the suggestion to check what kind of oil filter was used. If it was anything other than a premium name brand filter I would change it before doing anything else. The two-dollar white box oil filters are deadly. A premium oil filter is cheap insurance.