✅ SOLVED Bullet? Small bomb?

[Detector mom]

Found near old house site occupied/used from early 1700s to now. Many of my finds in this particular area of the site are from late 1800s-1920s, with pop tops and modern garbage here and there. Little shield says “e.t.c.” The top (or bottom?) seems to say REM— beneath all the numbers.

 

[ticndig]

[FONT=&quot]Electrical Testing Laboratories. [/FONT]

 

[DCMatt]

It's the "starter" from a fluorescent light fixture.

 

[Anduril]

Matt beat me to it.
That's exactly what it is. (I remember these from the 1970's, but they pre-date that.)

 

[bradyboy]

their still used today
brady

 

[Detector mom]

Thanks, all!!! I never would’ve guessed and found it hard to research. I do believe someone thru the years used this building’s old out-kitchen as a darkroom or shed in the 20s-50s before it was torn down. Found a vintage darkroom timer not far away from this...