The socket spring is sprung. The buzzing says you have arcing in there. Very bad news. I suspect the wire is getting loose because it's a type of connection we call a "back stab" where you jab the wire in a hole and a barbed spring grabs it, I bet that has also sprung. I would shut off the breaker and swap the outlets for quality grades.
How do you learn how to do that? Libraries and big-box home improvement shops have a collection of books that teach home electical repairs. Look through all of them and find one that "speaks to you".
When you shop for outlets, you'll find there's a 75 cent tier, a $3-4 tier and a $10-12 tier. You want the $3-4 tier.
Never use the "back stabs" on the outlet where you jab the wire in, and it grabs it. The springs are unreliable - this very thing happens. It is OK to use "clamp-screw" types where you stick the wire into a slot and then screw down the screw to clamp it down. Those are in the $3-4 tier. Or use the screw terminals.
Also be on the lookout for "aluminum wire" - it is silver or gray instead of orangish copper. Aluminum wire requires very special handling - check back here.