Mystery Electronic item. Maybe an electric metronome, or timer that clicks seconds

Hello all, reaching out once again for assistance identifying this item. It is a metal cabinet. Has a power cord. It has 2 vent screens on the cabinet and a speaker. The knob serves as an on/off switch and volume control. When powered on it takes a few moments to activate. It generates a clicking noise similar to a metronome, but there is no adjustment for the frequency of the clicks. . There are no other input jacks or means of connecting another device.
I tried to open the case but the back offered some resistance after I remove the screws so did not want to force it.
Any assistance is greatly appreciated.

9/25 UPDATE: I was able to open the box somewhat. What I can see inside is a 117L7/M7GT tube, an ASTRON 2.0MF capacitor, A transformer , A Mallory TCD capacitor and a few transistors. Also the volume control and lamp fixture. I added pictures of what I was able to see inside
Regards