Where can I find Cathode Rays?

Answer 1

Cathode rays are in a vacuum inside of a picture tube. A CRT or Cathode Ray Tube as they are called, is the standard for computer and television display used prior to LCD (Liquid Crystal Display) or Plasma. Cathode rays must exist in a vacuum (picture tube) in order for the cathode to emit a ray of electrons.

Answer 2

There are no such things a "cathode rays." A television tube, a radar display, and the computer monitor in front of you is what's normally called a cathode ray tube. High-speed electrons move from that part of the cathode ray tube called an 'anode' and impact the backside of the screen, causing it to glow.