Could I use a ceramic heat emitter in this snake tank instead of a heat lamp?

Red bulbs give of low vis light to reptiles which does not bother them. Any heat source inside of a reptile's cage could be a burn risk to the animal. If you decide on a CHE, it is best placed over a screen top just like a heat lamp. By looking at your snake's cage, You can use the inside bulb sockets for lower watt non heating bulbs, one white one for visual daylight and one red one for viewing your snake at night. Cover them both none the less. This will be the cool end. On the other end, you can use a heat pad under the tank or, a CHE safely over head. Sometimes both are needed to provide the correct cage temperature. This will be the hotside. Regular red reptile bulbs do not deliver as much heat as red infrared bulbs do.