How to set a not plugged in pin to ground or Low I have digital pin 7 when set to High it does and when set to low it does not.

The only way I can get consistent High or Low is to use a 2 position 3 pin switch with my pin 7 in the middle and ground on one side and 5v on the other.

Is there a way I can use an simple Open/Close switch and still get the same function?

As of not if I dont "pull" pin 7 to ground I get both open and close randomly.
Seems like you already found the solution. Without a pull-down of pull-up resistor, the voltage at pin 7 will float to some random voltage, when the switch is open. 

Either add an (external) pull-down resistor. Or flip things around and use the internal pull-up resistor inside the ATMega328p. Then connect the other side of the switch to GND. Whenever the switch is pressed, your digitalWrite gives you a LOW. 

To use the internal pull-up use pinMode(7, INPUT_PULLUP);