2.4L engine with a significant engine oil leak!

The oil leak (at least a quart a day) appears to be coming from a plug looking thing jutting from the back of the oil pan about a third or a fourth of the way up the engine block from the bottom. It has a thin wire coming from it leading to who knows where. The oil seems to be coming from the plug, running down the wire, and dripping off of it. I think it might be the oil pressure switch or the oil pressure sender. Are the switch and the sender two names for the same device? And am I right about what that thing is? I need to know so I can get the right part from the store and try to replace it; I can't afford to take it into a shop right now. P.S. It only leaks out (significantly) when the engine is running. P.P.S. I attempted to donate for this question but it kept on repeating that I needed a minimum of 2 dollars even though every time I filled out the payment information, I put 2 dollars in the respective field. Thank you.