How do I spot a bad sober living house before moving in?

Visit in person, always. Green flags: NARR certification (or your state's equivalent), a written resident agreement, real house rules with drug testing they can explain, a house manager who's reachable, and residents who'll talk to you. Red flags: cash only, 'move in tonight' pressure, overcrowded rooms, no visible structure, or — the big one — the house requiring you to attend a specific IOP they're cozy with. That last one can mean the house makes money off your treatment, not your rent, and those places have a way of evicting people whose insurance runs out. Price alone tells you almost nothing; the contract and the visit tell you everything.