Greenfield police are warning residents to monitor their mail and financial accounts after a USPS mailbox outside the Greenfield Post Office was broken into early Monday morning.According to police, someone pried open the exteri or mailbox at 7353 W. Forest Home Ave. during the early morning hours of June 22 and stole mail from inside.For Diane Conrad of West Allis, the latest theft sounds all too familiar.Conrad said checks she mailed from the same mailbox in 2023 were stolen, but later recovered after Cudahy police found them during a traffic stop.Watch: Greenfield police warn residents after mailbox theft 'How many people has this affected?': Greenfield police warn residents after mailbox theft"I didn't know they were stolen. I just anticipated they were okay and mailed them off," Conrad told TMJ4 News.Three years later, Conrad said she is frustrated that the mailbox is still being targeted."I was in 2023, and that was almost three years ago. How many people has this affected?" she asked. Greenfield Police said the mailbox has been targeted multiple times over the past several months despite efforts by the department and the U.S. Postal Service to prevent thefts.The U.S. Postal Inspection Service said it is aware of theft issues at the location and is assisting local law enforcement with the investigation."The Postal Service has implemented several security upgrades at this location to help prevent future theft," U.S. Postal Inspector Jeremy Leder said in a statement to TMJ4 News.According to Leder, the Postal Service installed a new collection box with upgraded locks and other security features designed to make it more difficult to break into.The outdoor collection box currently has a sign posted on it that says "Please don't put any mail in the collection box"."I went inside and dropped our mail off in there because I just didn't want to take the risk," Victoria Peterson, a resident, said. "I initially thought just over the past few weeks, but to hear so long, it's quite startling," she said. Police are asking anyone who deposited mail in the mailbox between 3 p.m. June 20 and 2 a.m. June 22 to closely monitor checks, financial documents, and any mail containing personal identifying information.Anyone who notices suspicious activity or believes their information has been compromised is encouraged to contact their local police department.Residents who believe their mail was stolen should report it to local police or the U.S. Postal Inspection Service at 877-876-2455 and review their financial accounts for fraudulent activity, Leder said.Conrad said she advises others to avoid outdoor collection boxes whenever possible."Don't use the boxes. I hate to say it. You're trusting, but not everyone's honest," she said.Greenfield police are still working to identify a suspect. The investigation remains ongoing.This story was reported on-air by Kaylee Staral and has been converted to this platform with the assistance of AI. Our editorial team verifies all reporting on all platforms for fairness and accuracy.Its about time to watch on your time. Stream local news and weather 24/7 by searching for TMJ4 on your device.Available for download on Roku, Apple TV, Amazon Fire TV, and more.Report a typo or error // Submit a news tip ...read more read less