Electrons 'popping' out are more of an analogy describing the electron field and the location of the electron within that field.
There is an electron field, the electron could be anywhere in that field. If we measure, we find it at point X. If we measure again (in some extremely tiny space of time) its gone from that spot and is somewhere else entirely within the field... just as though it 'popped' out of existence at point X and popped back in at point Y.
Its like the electron is 'everywhere/anywhere' in the field until we measure it, then its in some place, then its 'everywhere/anywhere' again until we measure it again... then its somewhere else.
Of course, that's not a correct analogy either.
It is not surprising that our language should be incapable of describing the processes occurring within the atoms, for, as has been remarked, it was invented to describe the experiences of daily life, and these consists only of processes involving exceedingly large numbers of atoms. Furthermore, it is very difficult to modify our language so that it will be able to describe these atomic processes, for words can only describe things of which we can form mental pictures, and this ability, too, is a result of daily experience.
- Werner Heisenberg