There are plenty of threads with accurate legal information on this board. Please read them and make sure you understand the risks you and your MA or companion may or may not be taking.
When massage parlors are raided by the police, the owners are usually charged with running a common bawdy house, living off the avails of prostitution, etc. The men who are there at the time are charged with being found in a common bawdy house.
It is illegal for a companion to offer erotic services from her home. Doing this "regularly" qualifies as operating a common bawdy house, even if she is the only person who lives and works there. If she rents the place, the landlord may be charged with living off the avails of prostitution. If she has a partner or spouse, whether they're in the sex trade or not, they may be charged with living off the avails, too, because they are benefitting from the companion's income.
However, it is rare for independent providers to be charged if they work discretely and don't create a disturbance in the neighbourhood. We're not seen as trouble-makers and so the police rarely pay attention to us.
It is illegal for a companion to offer services from a hotel room that she has rented (it becomes a bawdy house). However, it is NOT illegal for her to meet someone in HIS hotel room and exchange services for money there. Providers who offer this kind of outcall service are working completely legally. It's also perfectly legal for a companion to go to a client's home, though for safety reasons, many will do outcalls to hotels but not to private residences.
See an independent escort! Exchange e-mail with her and talk to her on the phone. Get to know her a little bit before you see her and you'll be sure to have a very nice time. You'll also know that she gets to keep 100% of the fee you pay since there's no agency taking a substantial cut.