That cup of joe may do more than just you up in the morning.

FOX's Colleen Cappon reports in today's "Housecall for Health"...

That coffee keeping you going through the day could also be causing you to hallucinate.

Australian researchers tested people with varying caffeine intakes and stress levels, and found that, for more than half of those tested, high amounts of coffee and stress were a lethal combination.  The result?  They were three times more likely to see or hear imaginary things.

Those people with high levels of caffeine heard Bing Crosby's White Christmas playing amid static.

Or at least they thought they did.