On 31/07/2018 18:56, Terry Schwartz wrote:
My assumption has always been household cooking grease. Any hard surface that doesn't purposefully get cleaned regularly in a house where actual cooking takes place seems to accumulate airborne cooking grease. It soaks into soft surfaces, but creates an oily film on everything else.

Used to make a lot of service calls into houses in certain ethnic neighborhoods. Bring TV sets back to the shop... first thing we did was wipe them down with glass cleaner. The ammonia in it worked much better than the "409" type cleaners of the day against cooking grease. Some sets were so greasy there was a real risk of dropping them on the way out of the house. Sometimes the line cords were literally furry with grease and accumulated dust. And the high voltage sections, even worse.

You may be referring to something else... that was just my observation.



Do you happen to know what the oily or slimy stuff is, that coats old
very flexible cables such as telephone movable extension cables, a
bio-film or plasticiser like chemical ?


I recently dumped a box of telephone stuff ,been in a shed for 20 years,
perfectly ok when put in there.
All the leads were this manky gooey coating, no cooking in my shed of
coarse.
I'm reminded of the black goo in tape recorders/VCRs when a rubber band
perishes to goo, and all the other bands get the same contagion and fail
, but not necessarily to sticky goo