None of the above!
You must be isolated from the mains.
Try a toroid transformer. Toroids have decent frequency response, smaller is usually better. Perhaps a 10VA totroid with a 6V secondary? Turns ratio and how the winding is made up will effect the bandwidth, but you can count on at least a few hundred kHz, and spikes at higher frequencies will still be visible on an FFT.
What frequency range do you want to examine? Lowish frequency harmonics caused by rectifiers or non-linear loads, medium frequency disturbances, or VHF perturbations caused by PLC for example?What hookup method do you suggest - fuse then capacitor followed by a voltage divider? Analyzer input impedance is 50 ohms.