I swear people never read the pins…
This is all you need.
#showtooltip
/cast [mod:alt,@player] [@mouseover,exists,nodead] [] Holy Shock
[added]
Correct, you cannot mouseover your 3D self (or click it), otherwise you’d never be able target anything at your feet, you’d always be in the way.
Mouse buttons cannot interact with unitframes without using an addon like Clique, they eat all non-default mouse interactions.