Q....On a circut/outlet tester what does open ground...open neutral...open hot... hot/ground reverse...hot/neutral reverse actually mean Thanks for taking the time to answer.
 A....The ground stands for the equipment grounding wire (green). The neutral is the return wire (white). The hot wire is the live feed (black). An open means the wire is either broken, disconnected or was never there. Reverse means exactly that.

Q....Can you tell me what reverse polarity is and if it is or is not dangerous?
 A....Reverse polarity in Alternating Circuits is when the hot/neutral wiring is reversed. Yes this could make the neutral live and present a shock hazard.

Q....I recently hung a new cieling fan in our master bedroom. The fan itself had a black, white and ground wire which were connected accordingly to the same house wires. A red wire that was originally connected to the old cieling fan is attached to a dual switch on the wall that controlled the light on the old cieling fan seperately. Since I have no red wire on the new cieling fan I simply capped off the red wire coming from the house and tucked it away. Problem.....Even with the red wire switch turned off the new cieling fan light turns on and off at random. I am very concerned as it seems this could be hazardous much less irritating. Any advice as to what is wrong? Thank You
 A....Hard to tell the problem without being able to check the wiring. I have an idea what is wrong but it is not a good idea to guess when dealing with electrical wiring.

Q....What do the terms..open and close a circuit mean/ thanks
 A....An open circuit is one where no current flows. A switch in the off position would indicate an open circuit.
A closed circuit is one where current flows. A switch in the on position would indicate a closed circuit.

Q....Does the small and large blade on a receptacle have a meaning? If so what?
 A....If the outlet is wired correctly, the small blade slot on the receptacle should be the live wire (black) and the large blade slot the neutral. (white).

Q....How can you tell the temperature rating of Romex used to feed lighting fixtures?
 A....Look for the letters NMB on the jacket of the wire. The NM means nonmetallic sheath cable (Romex) and the B suffix means that the cable's conductors are rated for a maximum operating temperature of 90°C 194°F.(Article 336-30-(b). We can assume that wiring made prior to 1984, without the B suffix, is rated at 60°C 140°F. This is the type of wiring found in most older homes that were built before 1982.