Some videos with the glass in and the lights in the room off. Note, my game has purple spotlights in the rest so that is the hue you are seeing. The lamp in the actual spotlight is a 12v amber automotive bulb that I can recommend.  

Here are some of the flickering effects that I scroll through. They have various patterns that change between more of a fade in and out to a combination of fading effects with random flickering. 

Arrrr matey, yer light be flickering! Add a more authentic gas/flame light feel to any spotlight on a JJP game. This easy mod just plugs right inline with the spotlight power under the playfield. Installs in just a few minutes. 8 different modes to let you select any sort of flickering pattern you can imagine and several speed options for each mode. Works on groups of spotlights (as long as they share a common power plug) and has the option to just be a dimmer (no flicker) if you decide to go back to a solid light but want to control brightness.