Safety Capacitor X-Y In Farfisa Organ

[sarakisof]

Hello everyone, in progress of this post https://www.diystompboxes.com/smfforum/index.php?topic=123142.0 having solved the Reverb issue and having my Farfisa Foyer running totally perfect so far, i got in mind a last small "issue" that i ocassionally have. Well i get a little (really small) 50hz and 100hz mixed hum, i guess it is normal (actually it is lower compared to guitar tube amps i ve heard so far - almost non audible while playing at normal medium volume anyway).
But you know, the more you search on forums the more you learn. I don't know how i ended up reading about it (messing around google  ) i read in one of those antique radio forums about usage of "death" safety MKT X-Y type capacitors and how useful they can be.
So i remembered that my Farfisa Foyer used one of those old 50's paper safety capacitors and that i replaced it with a simple Polyester same value. Well i know i am OK, but in terms of minimising noises interferances atc. as much i can, could it be better if i use a proper Y2 MKT safety cap instead of the Polyester one?

Original paper cap used was rated 0.0047 47nF 630V. and as you can see in the pic below it is used between Live/Neutral and Ground.
Something else: I have also replaced power cord with 3 prong, as the original did not had ground wire - actually the cable had the yellow green inside but it was not terminated/connected to the terminal cord, it was just cutten and only Live Neutral connected to mains. Ground wire's first point connection was at On/Off switch and then it gotted down to the safety cap...

I read in an other vintage radio forum that about 630V would be OK if i use simple Polyester, but i just wonder if a Y2 MKT dedicated safety cap would make things better a bit at least in terms of noise.

[PRR]

If you have a GOOD wall-ground to chassis, you don't need the cap.

If you must use a cap, YES use one rated for the job. Too many ordinary caps fail over time and they sometimes fail short. Line-rated caps are designed to fail safely.

[sarakisof]

Ok thanks PRR