The squib should be a comment on some aspect of syntax. You can discuss some theory that we developed in class, perhaps noting data that seem problematic. You can consider some new puzzle that we did not discuss. You can apply the theory developed in class to some language which we did not consider.
Your squib topic is due this coming Thursday (November 16). The topic can be a single sentence ('I plan to write about X'); the idea is to make sure you're thinking about the squib in time to have time to write it, and to give us time to give you ideas about things to read and think about. Handing in a topic doesn't commit you to writing about that topic, necessarily, so don't delay handing it in because you're afraid of getting the topic 'wrong'.
Here are two places you can look for papers to give you ideas about things to think about (these papers are generally written by professional linguists for an audience of linguists, so they will probably be very challenging to read!):
Feel free to discuss your topic with us, before and after handing it in.