Let me start by saying I don't really know what I am talking about, so my vocabulary may be incorrect. This is all based upon my best interpretation of the problem.
I am replacing some old light switches throughout my house. Each of the three bathrooms have an exhaust fan and lights that are on separate switches in the same box. In two of the bathrooms, there is a separate ground and hot wire for each switch. In the third, which seems to always have the most issues, I opened to box and I only see one ground and I believe only one hot. There appear to be separate wires leaving the box for the light and exhaust fan. It also looks like there is a wire that is only connected between the two switches. My guess is that this is because there is no hot wire for the other switch, but I'm not really sure. All of the wires appear to be attached using the terminals, with the exception of the wire between the switches which uses the push ins in the back.
I would like to replace the switches, but have no idea how I should wire them. Also, is this wiring setup the reason this bathroom has issues with switches/lights? Any help would be greatly appreciated.