"Old vacuum tube on the wall in the living room in my new (1910) home. The thing I’m holding is the cover."
A: "It’s what we used to call a bee hive light. Sometimes used to provide a visual cue to a hearing impaired person that the phone or door bell is ringing."
Thanks Internet.
"... and the liquid will drop through the slit in the middle."
Let's keep it clean; this is not an AO site.