Get an Amprobe metering device. It clamps around the AC wire, usually in your fusebox(clamps on a single conductor)either the hot or neutral line for the circuit you want to measure. Or you can rig an AC extension cord with an opened jacket, & measure with that in series with the load in question. Use caution; don't do this if you don't understand the risks, because you could be electrocuted. Also don't do any critical listening when rigged this way for measuring; it will probably sound awful. Quiescent current measurement will be lower than with signal applied (to a power amp) outputing any appreciable amount of power.
How can I measure power draw?
Is there a simple way to measure how much power my components are drawing from the wall? My interest is prompted by experimenting with the PS Audio Power Plant and various conflicting info about how much it draws. (The answer I'd love to get is that there is a Radio Shack box I can stick in between the DUT and the wall, but you tell me...)