(Picture in comments)
This box is wall mounted. The aesthetics look like an electrical box, rather large, right next to the AC condenser, and has a mechanical mess inside, with a foam insulation.There are two copper pipes coming from it, one has deteriorated, and is now spraying a lot of water inside the box. The markings on the box are almost completely gone, but what little I can make out indicated that it's a pump of some sort, related to "refrigeration". I thought maybe a condensate pump, but it's very large, and involved for that.Furthermore, we had a new air conditioning system installed a couple years ago. The installer didn't know what the box was, and asked if they could remove it. So, to the best of my knowledge it shouldn't even be in use with the new system.Does anybody even have an idea what this thing is?