Being safe, extra safe or asking questions is never dumb.
Here is the portion of the schematic showing the game voltages for Aquarius*. As already stated I would be most concerned with the wires carrying wall voltage which should have plastic insulation rather than the cloth insulation of the 6 & 25 VAC wiring.
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You will have 110/wall VAC at the line cord, main line fuse, power switch, transformer input, the 2 big control bank reset coils & their 2 fuses, 2 score motor switches and a switch on the SB armature. You probably felt Gottlieb's 24 VAC.
I like to use a power strip under the game that you can toggle on and off to kill power without needing to plug & unplug all the time when working on a project game.
*Older Gottliebs also have 110 VAC on some coin door stuff, a slam switch, replay unit, ball release unit, etc. Other manufacturers used different voltages at different times.