https://www.youtube.com/watch?v=FngeV7yi6N4 This is a short video I made of a $30 plasma lamp I purchased on eBay. I something similar growing up but it was spherical. This once is a cylinder that is compressed in the center.
You can buy one here. However, after owning it for about two months, I can tell the tube is already out-gassing and probably won't last more than 6 months.