Help to identify communication device

[unidentifiedobject]

Hi everyone,

I come to this forum looking for answers. I have come across an object that I believe to be military and pre 1960. I've asked several military museums and experts but have yet to get a positive ID on what this actually is. It is cast aluminum and on it are the words "tone" and "voice". I think it's some type of radio casing. But in all my research I have yet to come across anything similar. I'd love any help or theories on what exactly I have here. It was originally found in a junk yard in the 1980's in Souther California. That's about all I know. Below are pictures. Thanks guys!!!

[unidentifiedobject]

sorry if this is posted in the wrong section. That was my mistake, hopefully most will see this. Thanks.