Hi. It might be a good idea to post a list of which pins cause the LED to glow faintly and which brightly. some GPIO pins have other uses to that can affect things that are connected to them. it also makes a difference on how you connect the LEDS, you should be connecting them GPIO pin > Ground, if...

Just started using my Raspberry Pi now that school is out. I connected the T-shaped cobbler and I was following a few different tutorials to get used to the GPIO set up. I began to notice that when ever the LED was connected to ground and certain pins it began to glow (some times faintly other times...