floating pin

So, I've been dealing with a floating pin for some time now. Every time I assign an input pin, it just senses 5 volts out of thin air. I saw a video that says I have to put in a pull down resistor, which I did just as the video showed me, but so far nothing has changed. Help please? I really want it as it was previously.

What value of resistor? Where did you connect the resistor?

See these 3 examples for wiring switches to an input.


What was it "previously"?

What was it “previously”?

Previously, it worked as they always should: with the input pins sensing 5V when its supposed to.
I found another video about this, but it only fixes the problem temporarily.

Show us a good schematic & image of your circuit wiring. Posting images: http://forum.arduino.cc/index.php?topic=519037.0