it is probably i stuck switch behind a rubber bumper....put in switch test, maybe more than one actual switch uses that switch number....

https://www.ipdb.org/files/1796/Williams_1986_Pin_bot_Manual.pdf

Page 29

Which switch is it? Is there a cap on the switch? The cap may be failing.

Here is the matrix:

0F8781C1-D2D7-4C2A-A323-A897592DFA86 (resized).png

Looks like switch 56, 59 and 60 are the only 10 point switches on the game. You can see them on column 7 & 8 on the switch matrix chart.

(Apologies, i had to edit my post to include 59 as another commenter pointed out)
669963670.png

59 to

Sorry. Just realized you can’t figure out which switch it is. There is likely some other clue to the switch. A light or sound associated with the particular switch. Play around with the switches to try to locate it.

It could be the wiring lugs on one of the switches got mashed together or a diode got bent somehow and is contacting something it shouldn't. I'd take a look at the switches from underneath the playfield and make sure everything looks ok there.

Are you sure there isn't a switch that is gapped too closely? This is very symptomatic of coil vibration triggering a switch. Perhaps stick a piece of paper between the contacts on the 10 point switches previously identified so they can't close and flip the flippers. Will it still happen?

Did you put the game in switch test mode and see which switch appears to be activating?

Did you take the rubbers off and bend every possible offending switch open so they are not nearly anywhere touching each other?