Not a project, but something at my work many years ago.
At the TV transmitter site I worked at, we had a "Flying Spot Scanner", which was used when needed to display the station test pattern or apology for lost programme, or whatever. (we had a box of BW slides).
This thing was full of tubes, & was used every day, so one of the weekly "routine tests" was to measure selected parameters of the device, switchable on the front of the devices.
To this end, we had a dedicated meter in a small metal enclosure with a lead terminated in a 1/4" jack plug, which plugged into socket on the FFS.
The plug wasn't just a bakelite one , but was made from moulded rubber, which had perished, allowing access to the inside connections.
It had received a "bodge repair".
It had another problem, in that the meter would sometimes stick, but this could be overcome by unplugging then immediately re-inserting the plug.
Being sticky, the needle didn't drop back to zero, & the "nudge" freed it to go to the correct reading.
The meter was particularly troublesome this time, & although I got it to work several times with this procedure, it eventually refused "hard" when I was trying to read the HT supply.
As I fiddled with the plug, the "bodge" repair failed and I got a nice HT "belt".
In a rage, I threw the thing across the room, where it ended up hitting the bottom of a rack!--OOOPS!

Somewhat abashed, I took it to the workshop & made an elaborate repair, removing any chance of touching the "hot bits".
Expecting the worst, I plugged it in to find it now worked perfectly, with not the slightest sign of sticking.