So I went in my room to play guitar the other day, I plugged in turned my amp on and just played some Smashing Pumpkins. I was playing and everything was going good until I noticed a squeak, I got it every time I hit a dead note. Trust me on this, it was not a sweet harmonic, it was almost like brief feedback that raped the ears. Now I'm just wondering what's the cause, I'll give you a brief rundown of my gear:

Yamaha Pacifica - stock pickups
Roland Cube 60 (clean channel at the time)
Dunlop Crybaby Wah (was off at the time)
Electro-Harmonix Big Muff PI (was on)

Everything is relatively new, got the Big muff pedal for christmas, bought the crybaby this past summer, and got my amp for grading/my birthday/easter (had to convince my mom). The only thing that's old is my Yamaha, it's about 2 years old, the pickup selector is sh*t but aside from that it's in working condition. My patch cords are fine except one that i turned into a killswitch but everything is sealed up with electrical tape.

Could you please help find the source of my troubles?
does it still squeak now?
My gear:
PRS SE custom
~!~--Peavey XXX super 40 EFX --~!~
Peavey VK 112

===WGS Vet30
===JJ power tubes

-ISP Decimator
-Digitech Bad Monkey
-Crybaby wah
-Korg Pitchblack
-Danelectro FnC EQ
I think it's called a "mistake"

When you make them, ugly noises come out of your amp.
Quote by Mitchell?
I think it's called a "mistake"

When you make them, ugly noises come out of your amp.

oh, Burn.
But thats this only thing I could think of.
Its not an electrical problem.
Yamaha RGS-121
Boss ME-6 multi-effects
Boss DS-1

New things are in order.
Yes it's an actual squeak, and it still happens. It's not a mistake retard, I'm pretty sure you shouldn't get a squeak while playing a dead note on the lower frets. I've ruled out harmonics too because the way i place my hand when i hit dead notes is full hand, and thus i'm covering the strings at different places. But it sounds like feedback high-pitched and fast, thanks for the help *rolls eyes*.