Below is the typical circuit when somebody do the "test light" on wall electricity socket (Image 1):
In this "images 1", very little current will flow into his body, because the high electrical resistance of the "Test Screwdriver", then the "Test Screwdriver" will produce light.
But if that man do the "test light" using below method (image 2), will bigger/lethal current will flow into his body than in "image 1"?
Assume that same power source, and same "Test Light Screwdriver" used in both "image 1" and "image 2".
Best Answer
If the man is totally isolated from any other circuit path the current through the man would be the same regardless of order.
However, the possibility of inadvertently touching something else during the process, e.g. putting a foot down, makes this a highly inadvisable experiment.
BTW you may find this cross post interesting. Wearing rubber soled shoes is highly advisable when using these testers.