Wild Shape won't help
This is because this ability doesn't change your type. It functions like Alternate Form, and Alternate Form states
The creature retains the type and subtype of its original form.
For other abilities, ask your DM
There is a thing called constant targetting (check here and here, with thanks to @HeyICanChan for his search). In short, it is not entirely clear if d&d 3.5 uses it or not. So, it is unclear if effects check if target is valid... each turn? Each action? They clearly check when they are applied, but after that it may be played both ways.
I may say, I would allow someone using Still Silent Polymorph to escape Hold Person via it. But its just me. On the other hand, Main D&D FAQ (which is sometimes approached with skepticism
), for example, disagrees, containing the following exchange
Q: If, while under the effect of a spell that depends on type (such as hold person), my character is transformed into a different creature type by polymorph, does the spell’s effect remain?
A: Yes. A spell only checks to see if you are a legal target when it is cast. If you become an illegal target later (such as via the polymorph spell), the spell remains in effect.