Depends on the plastic - acetone (nail varnish remover) can easily soften some plastics. IPA (isopropyl alcohol, rubbing alcohol) is a good solvent but much less likely to attack the plastic, I'd suggest that instead.
The best stuff I have found for removing gluey residue is WD40. Spray it on and leave it a while then wipe off. You're bound to have some at home somewhere.
https://www.youtube.com/watch?v=6o0sXafcff4