Police said the boy was peering over a festive display while trick-or-treating at a neighbor's home when the costume ignited Sunday night.
``As the child leaned over the table to look inside the novelty item, apparently his costume caught on fire,'' said Sgt. Henry Stormer.
The homeowner, 53-year-old Richard Reyes, tried to save the boy and was burned himself.
The child was burned on his head, neck and hand, police said. He was taken to Bridgeport Hospital and underwent surgery for several hours Monday, according to televised reports.
It was unclear what costume the boy was wearing. Police said they were working with the U.S. Consumer Product Safety Commission.
A woman who answered the phone at the Reyes' home said she would not comment.
