Lets just ignore painting common 'plastics' like styrene and think about wheels for a moment.
Early plastic wheel centres were moulded from nylon, which is not affected by any of the common solvents used in cellulose paints. However it has an 'interesting' property in than it is hygroscopic i.e. it will absorb moisture from the air and expand. Usually the air is not humid enough to affect the friction hold on the axle, but one of the major constituents of cellulose winners is ethanol which is highly hygroscopic, and forms a pathway for the nylon to absorb more water. The effect of a slightly expanded centre and rubbing the paint off the tyres is very likely to move the wheels on the axles, just as Larry described.
Baking the wheels, with or without the loco, at 40 - 70ºC will expel the absorbed water and shrink the wheels to their original size.
Wheel makers have, over time, changed the material of their centres first to glass filled nylon and later to ABS which does not absorb moisture. So if anyone has any 'classic' plastic centred wheels from the 70s or 80s lurking in their maturing cabinet then, I suggest they should quietly change them for more modern examples.