House may be posted twice, by realtor and owner. Best is to drive around the area and look for "Se Renta" signs (for rent). If it is not a realtor, then it will be the owner. Gated comunities, ask the guard if he knows of places to rent inside and if he will let you in to fet the phone numbers to call. Alsi signs for Se alquila which is the same as rent (2 words for the same)