Mildew over shower

[smilner01]

I have a 42x52 shower with 9' ceiling and 7' door opening that we have had mildew problems with ever since we moved in. The tile goes up to just past 7' and then paint (we repainted with the mildew killer primer...didn't work). There is and exhaust vent outside of the shower, but I feel the shower holds the moisture in the ceiling of the enclosure... Should I put another exhaust fan in the shower enclosure or get a pass through vent from the shower to the bathroom closer to the ceiling?

Also there is a can light in the shower enclosure, if I vent in the enclosure are the vents that are the light vent combo that fit in a can light hole ok to use?

 

[Fitter30]

Use a timer like this then fan will run 30 minutes after a shower to get all the humidity out of the room and the plus don't have to worry about not forgetting to shut it off.
https://www.amazon.com/gp/aw/d/B00SNU8EUM/ref=sspa_mw_detail_4?ie=UTF8&psc=1