Well I'll probably have tons of people disagreeing with me but here it goes........I think tattoos in someones house CAN be safe. It depends on the house itself, how clean the equipment is and whether the artist knows how to keep things sterile and clean. I have had three out my four tattoos done at my house(my husband is a tattoo artist). I have never had ANY problems with them. No infections, no problems WHATSOEVER. And I know that he has also done at LEAST ten other tattoos out of the house as well. No problems with those tattoos either. In fact, some people have come back to have another tattoo done.So for me, I like having them done at home where I am more comfortable, BUT if you don't know the person very well or the house isn't clean I wouldn't do it. It all depends on trust and your safety. If you feel safer going to a pro shop, then go for it! But even some pro shops aren't as clean as my house (lol). My advice is to research as much as you can before choosing who will do it and where you will get it done.
My husband has been doing tattoos since the 80s. He has had his own shop two different times and now does the odd tattoo out of the house.