how to make an ESD sensitive circuit?
What we did was to use 100x or 1000x scope probes and watch the signal on the scope.
If you don't have high voltage probes, then you can make some fairly easily with some resistors, but I would stick to only ESD, which is low power, nothing with substantial power behind it.

how to make 100x scope probe
Or
EEV video blog

Be aware that ESD, if not from a controlled source, can vary wildly depending on environmental conditions (mainly humidity), and can reach 200kV.