Electromagnetic wave is physical wave in that there is really a wave
propagating in space. But particles use a self-propagating probability
wave whose output can only be described by the wavefunction. We don't
know what's happening in between the source and the detector (in the
double slit) in contrast to EM wave which we know is caused by
physical wave. Yet the physical wave can interfere in the same manner
as the probability wave. Could there be a connection.

The physical em wave is also called classical wave while the
probability wave is called quantum wave. We know what
causes the waving in the em wave but not the quantum wave.
Yet their interference or behavior is the same. Could there
be some kind of connection that can give insight about the
origin of the quantum probability wave. Note when we mention
probability wave. The mainstream interpretation is that it is
not a physical wave but only a wave of possibilities described
by the wave function. So in the double slit, when an electron
is sent from the source. We can't say there is a physical wave
passing thru the slits unlike pure classical light wave where
there is a physical wave passing thru the slits. So the question
is. Somehow could there be physical wave propagating in
the electron experiment akin to em wave.