It happened in the vicinity of Forest and Longfellow avenues in Westfield around 12:50 p.m.
Authorities say the man broke in while the victim was out, and he brandished a knife when she entered.
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He allegedly attempted to sexually assault her, and the woman was able to fight him off and run to a neighbor for help.
Police were called to the scene, but the attacker had run off by the time they arrived.
They released a sketch of the suspect and urged anyone with information to come forward.
Anyone who may know this individual or has any information about this matter is urged to contact Union County Prosecutor's Office Detective Annie Coll at 908-347-2474 or Westfield Police Department Detective Betsy Savnik at 908-789-6078.
Members of the public are strongly discouraged from approaching or confronting any individuals they believe to resemble the suspect composite but are instead advised to contact members of law enforcement.
Tips can also be submitted anonymously by phone at 908-654-TIPS (8477) or online at www.uctip.org; submission of tips made in this fashion that result in an indictment and conviction can be eligible for a reward of up to $10,000 via the Union County Crime Stoppers.
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