You can do this rather easily using a modern Oscilloscope. You will need to play with the resolution, try several different Hz, from 100 Hz to several thousand per division. This is easy to see. I am an electrical engineer and this is a simple thing to do. Depending on your area, congestion and the type of loads, power can be very dirty. Your electric company generally is not too concerned about this. Simply Google "Measure noise on AC line."
Analyzing the power from the outlet
I've been reading threads on the various methods of power cleaning -- filters, regenerators, dedicated lines, etc. But I don't see a thread that explains a systematic way of evaluating the condition of the power at the outlet. Is there a thread or a link that instructs on how to analyze the power for noise, voltage consistency, etc from the point of view of an audiophile?