EMB-145 Captain reported an overheat in the # 2 air conditioning pack. After readjusting the regulator for the cabin; via the flight attendant panel; the Captain reported the smell of electrical smoke. The pilots ran the QRH and returned safely to the origin airport.

Narrative

While climbing through apx.16K feet an EICAS (Engine Indicating and Crew Alerting System) caution message illuminated along with the associated bell of PAC 2 OVHT. Also a status message of PAC 2 VLV CLSD illuminated. I went for the QRH but both messages disappeared within less than 20 seconds [they never reappeared throughout the rest of the flight]. The FO (First Officer) and I discussed what could have caused that and I speculated that it may have been from the Flight Attendant (FA) demanding too much of it by having too high of a heat setting. I checked to see the temp controller was set for the FA to have control and then called her over the intercom. Sure enough she said it was set to max. I asked her to set it to 75-80% because we believed it was being taxed too heavily and she said she would.About 2 min after that both the FO and I smelled smoke that had a distinctive scent of electrical wires burning. I called the FA again to see if she smelled smoke and she confirmed it (I believe she was in front at this time).I turned on my overhead light to start looking up in the QRH and it was then that I and my FO saw smoke wafting in the light. At that point I called to don the O2 masks and to execute the O2 mask donning memory items which we did and established communication. As my FO was flying I then ran the QRC checklist followed by the QRH. The QRH stated to close the gasper and recirc fans which I did. And it also stated to; if possible; remove the source of smoke. Since the smoke was associated with the appearance of the PAK 2 EICAS message and I had turned it off; I considered that it had been removed. We then [requested priority handling] and both agreed that return to ZZZ was the best option.I briefly considered diverting to another more nearby airport and looked around and at the MFD (Multi-function Flight Display) and into the FMS but ultimately decided to return to ZZZ as the smoke did not seem to be getting any worse at that point.I called my FA and gave her a brief on the situation and that we would be on the ground in 8-12 minutes and that she should wrap things up in 5-7 minutes and that we might deplane away from a gate. After this I made an announcement to the passengers that we had had a situation arise that was serious enough to require a return to ZZZ but I did not tell them what it was because I did not want to cause undue panic. About 5-7 minutes later when I had a little more time I called her back to give a formal brief.Dispatch queried us via ACARS that it appeared we were going back to ZZZ and wanted to know what was going on. I hadn't had time to call or notify them and I considered the problem serious enough to warrant a decision to return without their input. I responded to the ACARS and confirmed the return to ZZZ and the reason.We took vectors to get back and the descent and landing were uneventful with the only other consideration being overweight. Just prior to being turned onto final both my FO and I agreed it was safe to remove our O2 masks as the smoke had dissipated mostly and was not getting worse. Though we were able to communicate with them on removing them made it much easier. Just prior to the final approach fix I took the controls to do the overweight landing (overweight by approximately 308 lbs by our calculations) and carefully brought it down being sure to touch down with less than 300 FPM of vertical descent. I allowed the aircraft to float slightly to ensure a soft touchdown and took the second high speed ramp. Upon taxiing clear of the runway we ran the after landing checklist and conferred with the FA that there was no fire or smoke in the cabin and upon a negative confirmation I then confirmed over the radio with the Fire Commander on duty that there was no external fire. Deciphering there would be minimal hazard to taxiing to a safer area to deplane; my FO and I agreed it would be best to taxi to an area where airstairs could be arranged and we requested that.But Ground and the Fire Commander on duty were comfortable taking us to a gate and instructed us to taxi to the gates; which we did; with multiple fire trucks escorting us and uneventfully.Parking and shutdown were uneventful.