93 Intrepid hazard flasher switch problem

I just bought a 93 Intrepid with hazard warning signal doesn't work,
here is the detail situation:

The left and right turn signals work, and they use the same flasher(4
pins, pink, red/white, blue/pink, black wires) as hazard, so I believe
the flasher is ok. I used a multimeter to check the terminal voltage to
the flasher, when the turn signal is on, I can record a 12V over
red/white and pink, but when the hazard is on, I can only read 7.8V. I
think that voltage is too low to drive the flasher.

When I removed the hazard switch cap and column cover behine the
steering wheel, I was confused, under that semi-transparent red switch
cap just a plastic part with a hole, does it suppose to have a small
bulb? But I didn't see any metal contact inside the hole.

Any one can help? Thanks a lot!