As much as we have the heart to help, we would still need to keep ourselves and families safe while blessing others. If this is part of your profession for outreach mission, then the more you need to safe guard your safety, as well as all those around you.
Even if you are helping others on your own and not part of any organization or church but because you care and love people, preventive measures would still be needed. If the family that you are helping is for the first time, then getting to know them will be the first thing to do. I do agree with what
@Gracia Singh has said about not inviting them to your life and home till you know them. It is only when you feel comfortable and safe with them that you should let your family to be part of it. If you have young children, the influence that they get may become irreversible if you are not careful. This is not being judgemental or pessimistic but more for safety reasons, for you and your family.
Another thing to take note of, is whether if the families that you are helping are genuinely in need of your help or if they do, are they using their problematic situation to ensnare kind people to help them and in turn taking advantage of them? Many of these have happened - for example, financial loss - when the troubled family demands increasing more on financial help while the able people in the family who are capable of work choose to remain unemployed since financial support is made available to them so easily. Hence, there is no need for them to find a job to support themselves. Some others may require emotional support that they get so dependent that may directly or indirectly cause their helpers (like yourself) to become emotionally drained or worse still, burn out.
I personally have worked with many troubled individuals and families and some are quite extreme cases like crime offenders, family violence, drug addicts, etc. Hence physical and emotional safety and self-protection will always be at the top list.
Despite whatever we have said and will do, prayers will always be an ongoing and daily need of our lives. Meditate on Psalm 91 for God's divine protection, and take refuge under His wings. A thousand may fall at your side, and ten thousand at your right hand, but it shall not come near you. Whatever that happens or will happen, trust in the Lord with all thine heart (Proverbs 3:5-6).
I pray for you and your family's safety and protection in the name of our Lord Jesus.