Not sure of any block specific happenings but there are a couple family friendly events going on over the weekend.
Boo-Palooza will take place from 10am-2pm on Saturday, October 29th in Wicker Park, 1425 N. Damen. This is a free event with a costume contest for kids and dogs plus all kinds of other activities! More info can be found here: http://wickerpark.org/events/boo-palooza.
St. Mary of the Angels School is also having a Halloween Party from 2-6pm that same day in their auditorium at 1810 N. Hermitage. A $5 admission for kids (adults are free) gets food, games, prizes, costume contests and a haunted house. Find more info here: http://sma-school.org/