A PSA and a quick science lesson:
To initially get neon to illuminate, it typically takes at least 2,000 volts to get it glowing (sometimes much more depending on the size of the sign). That is a lot of voltage, and sometimes things happen. These photos from Federal Heath are good examples of why you should not touch our signs, especially the restored signs, or any neon signs at for that matter. That is a lot of power in there!