Squeal coming from relay box/area, I need help! Options

[Gooch]

So, I just recently got my car back from a blown engine. And a few days of driving a squeal started coming from, what we think, is the relay box. We have no idea what it is or why it's making the noise. It will come and go while driving. And when the car is completely off, no key in ignition, it will make the noise and then quit. So if I could get some ideas of what it could be and how to fix it, it'll be much appreciated!