Sparks from Flyback transformer

If the picture is the correct size then yes there is a small hole in the plastic of the transformer, have seen repairs done with silastic then mica in a few sanwidge layers but that is dependant on where the leak is and how long it has been leaking. Clean the area well, then with acetone or ceramic paint thinners, rub a small area over the hole which will melt the surface and block the hole. Then put on the layers of silastic and mica. leave the lot to dry for several days before switching on.

HV leakage is dangerous....change the transformer..they are not
expensive.....provide Make and Model for part #...........T.

This Repair is not recomended unless you live next door to your local fire dept.
This botch repair is a seriouse fire hazard & if has been undertaken by A proffesional they really need to think very carefully about changing there profesion.