Hi,
Yesterday we tried to connect a new ceiling light fixture. As per the instruction manual we connected black wire from building electrical outlet to the black wire from the light fixture and white wire from the electrical outlet to white wire from the light fixture. We had the switch to the electrical outlet turned off and had not yet connected the bulb to the light fixture. But as soon as we did the above mentioned connection there was a spark and the black wire of the light fixture burnt out. Please note that the black wire in the electrical outlet had 2 wires connected already to which we added(connected) the light fixture black wire. What was the reason for this spark when the bulb was still not connected?(I had assumed that the circuit should not be complete and hence should not produce any spark) As an afterthought we had the red wire from the electrical outlet connect to the black wire of our older light fixture.

Could you please explain the probable reason for the spark and how should the connection be made?

You should work with power off, if you must work with live wires, make connections with no load. In this case, remove the bulb(load).

Does switch control light, outlet or both?

Chuck