Im with DDD.
A breaker buzzing or constantly tripping could be a number of things.
Loose connections causing a heat buildup of higher resistance causing the breaker to heat up and trip.
A loose wire causing a short or a ground.
A breaker slowly wearing out due to its age and higher load.. like the load from your LR. Maybe theres too many consumers on that circuit.. how many doublers do you have on your outlets? Many 6 plug splitters?
Over time a breaker WILL wear out with a higher than average amperage running through it. It will become weak and with the higher heat will constantly trip.
Like DDD said, check the wire connections with a screw driver to your breaker, the connections on the other end of the wires your breaker goes to (hopefully yours are labelled. My panel was changed out in the past and when the new one was put in, they just hooked up the wires to the breakers so its a crapshoot to see which is which.) Change the breaker out. Like DDD said, Turn off the big breaker with teh power to your panel to make it dead. Just be aware when you turn it back on, depending on what power consumers you have in your house, you might have to reset things like your ac, furnace, etc.
When I do things like that, I wear gloves, check with a multimeter to make sure theres no power to the circuit, then go at it. If you cant use or get a multimeter, you can get those power pencils which you can touch to outlets or your wires in your breaker box, and if it lights up theres power.
If you dont feel comfortable with this.. get a friend or an electrician to help you.
