Rca tv electrical problem
If the TV is still operational, what you are hearing are probably high voltage arcing. Most common are in the anode cap area brought about by accumulated dust, grime and dirt on the outer glass envelope of the picture tube. This occurs mostly after a continuous or heavy rain or when the surrounding air is damp.
Since the unit is still operational except for the "sparks", this should only require cleaning of the above stated area. However, there are extremely high voltages even when the unit is off that perhaps you are better off seeking the services of a qualified TV technician.
Other possible areas of arcing are the fly back transformer, the horizontal output transistor PCB soldering points, the G2, Focus solder points. in some remote cases, it can be just inside the neck of the PIX tube.
Hope this be of some help/idea. Post back how things turn up or should you need further information.
Good luck and kind regards.