Turn Signal Switch Discolouration

[PeterMelon]

I'm looking for some advice as to what might be the cause of this type of discolouration on a turn signal switch. I was detailing a client's car and I'm not exactly sure if I made the appearance of the turn signal switch worse or did I just expose some of the damage that might have already been there. When it comes to turn signal switches, in my limited experience, 95% of the time any kind of discolouration is from oils left behind from our fingers and I usually use a steamer as it melts the oils right off, it's oddly satisfying. However, this one particular turn signal switch seems to have become even more "hazy" after steam cleaning it. I tried everything to fix it, from citric acid, to vinegar and baking soda... Any idea what this might be? I'm very curious to find out because the last thing I want to do is damage the vehicle that I'm trying to clean.
7429874297

[glen e]

Replace it, it’s cheap plastic that ages poorly, esp with body oils attacking it. Is the guy a smoker?

[PeterMelon]

No, not a smoker at all. At first I thought it was from hand sanitizer but apparently they don't use that at all.