(1 + c)/(r + e + c). The money multiplier (also called the credit multiplier or the deposit multiplier) is a measure of the extent to which the creation of money in the banking system causes the growth in the money supply to exceed growth in the monetary base.
A buzzing light switch could mean the fixture is wearing out, causing an arc of electricity behind the wall plate. If this is the case, the potential for an electrical fire may exist.
What's buzzing is the box on the wall. If both the chimes and transformer are in that box, I don't know which one it is. The box is loose now because I took the cover off, and the screws aren't tight into the wall. But when I first heard it buzzing, it was as tight as it's ever been.