What type of ceiling light?
How is it connected to the receptacle? Plugged in? Hardwired with cables in the wall?

it's an adjustable chandelier that could not be connected through the ceiling(no space) there is a cord that runs along the ceiling to the wall and plugged in to the wall outlet. See picture below.
http://www.waclighting.com/USA/products/?categoryid=39&productid=412

any suggestion would be very helpful...thanks!

I would start with replacing the receptacle. If that doesn't cure the problem, you may have a bad connection elsewhere on the circuit or a bad circuit breaker.

When you plug it in does it feel loose? then the outlet is probably worn out. Another problem the outlet wires are backstabbed,pushed into holes on the back of the outlet. That will cause you problems. Replace the outlet and put the wires under the screws on the sides.

Tomcathy: get that loose connection fixed A.S.A.P. Many house fires are caused by loose faulty connections. And also as mentioned above, Don't ever make a connection by using the push in wire connections on outlets and switches. I cannot for the life of me wonder why electrical code allows for such a connection. ALWAYS use the screw connectors! And make sure they are firmly tightened.