Are plugging in something that is turned on? A small spark is not unusual when the device or appliance is already on. The spark you see is the current "jumping the gap" because the the appliance is already calling for it. Try turning things off before you plug them in and see if the spark goes away.

Try taking a non-conductive item like a wooden spoon and trying to wiggle the outlet when there is nothing plugged into it -- does it still spark when it is moved? Does the whole outlet move -- that shouldn't happen -- it means the screws holding it to the box are not tight enough.

If so, then there is probably a loose or bare wire inside the box.

This is a fairly easy fix, even if you aren't used to electrical work.

1. Turn off the circuit breaker powering that outlet.

2. Check that the power is off by plugging in something.

3. Check again!

4. Unscrew & remove the cover plate.

5. unscrew the outlet, and pull it slightly out from the box, with all the wires still attached.

6. Look it over, and find the loose wire. Check that each wire is securely screwed down. Check that the wires are insulated up close to the screws -- no lengths of bare wire that could touch the box when put back into the box. Check that wires in wire nuts are twisted together securely and don't have bare wires sticking out below the insulated wire nut.

You will probably find something

obvious doing this, and can fix it easily.

7. Put the outlet back into the box, and screw down tightly.

8. Put the cover plate back on, and screw it down.

9. Turn the power back on, and test it again. Should now work without sparks!