You CAN get electrocuted, IF the capacitive coupling between primary and secondary provides 0.005 or 0.010 amperes.
But how large an area (overlap) between primary and secondary does this require, if the spacing is fishpaper insulation (old style transformers) of thickness 0.5 millimeter and relative dielectric constant of 5 (assumed)?
What is achievable in this coupling?
At 230 VAC RMS, or 300 volts peak, given 10mA requires 100 ohms per volt, the impedance of the capacitive coupling at 60Hz (377 radians / second) is 30,000 ohms
given 1uF at 1Hz is 160,000 ohms, and is 3,000 ohms at 60Hz, we'll assume we need 0.1uF capacitance between primary and secondary
what area of overlap, at 0.5 mm spacing and Er = 5?
Using C = Eo * Er * Area/Distance, we want the Area.
- Area = [(0.1e-6 * 0.5/1000)/45] * 1e+12 == 1e-7 * 1e-3 * 1e-2 * 1e+12
Thus a small transformer, operating at 230 VAC, will tingle you, perhaps badly, but should not provide the 0.01 amp (10mA) or the 0.005 amp needed to electrocute you.
Why? they may have 2" by 6" internal area of overlap of primary to secondary, but not the square meter of overlap.
Notice the design of large power transformers will place the primary and secondary coils in separate regions of the iron core.
This separation makes the capacitive coupling much small, even if thru mineral oil.
And if the iron core is GROUNDED, the coupling is smaller yet.
Remember these large transformers have to handle lightning strikes.
Thus physical distance between the windings ---------- is a survival strategy.