My Ex Is Using My Address For Probation Mail And A Probation Officer Came To My House. What Do I Need To Do To Protect Myself?

Location: Pennsylvania

My ex and I broke up last fall. We never lived together, but for convenience he used my address for a bunch of things while we were dating because he was between places for a while. I told him to change everything after the breakup and he said he did. Since January I have still been getting random mail for him, but mostly junk, so I kept writing return to sender and putting it back out. About three weeks ago I got a certified letter with his name on it from the county adult probation office. I did not open it. I texted him a photo of the envelope and told him to come get it. No answer. Two days later another one came, then a plain envelope from the same office, then one from PennDOT. At that point I got nervous enough to google him and found out he was arrested in December for DUI and driving on a suspended license. I also found out, through a mutual friend, that he has been telling people he "still technically gets mail" at my house and has been using my address because it looks more stable than where he is actually crashing.

Yesterday things got weird. A probation officer came to my door asking for him by name. I said he does not live here and has not for months. The officer asked if I was sure because this is the address they have on file and because he missed some reporting requirement. I showed her my ID with the address and explained the situation. She was polite, but she also looked around my porch and asked whether he keeps a car here or ever stays overnight. About an hour later my ex finally texted me and said I need to stop "making this a thing" and just put his mail aside because he is trying to get back on his feet and changing his address right now would "mess up his case." I told him absolutely not and now he is angry, saying I could get him violated if I tell probation he does not live here. My question is what am I supposed to do now to legally protect myself? Can I contact probation directly and tell them in writing he does not live here, or is that going to drag me into his legal mess? Also is there any formal way to stop someone from using your address for court or probation mail when they never actually lived there in the fi rst place?