If you don't have a lease that means that you're on a month to month basis so you should give about 1 month's notice in writing to protect yourself

If you have no written signature on anything, it is just a cash agreement, then I don't believe you have any obligation, legally. I am in NJ, and have seen people "just leave" without repercussion, other than the bad-mouthing they received from those that stayed. It would be nice to at the very least...give the landlord 30 days notice. That gives him enough time to clean it up & rent the place out again.

But I do not believe you are obligated to do so, and chances are, if you were paying cash and had never signed anything, that your landlord was pulling a fast one on the tax people, which more or less leaves you in the clear. So it is a matter of decency as far as leaving notice is concerned.

at the very least...give the landlord 30 days notice (60+ days in writing if at all possible.) That gives him enough time to clean it up & rent the place out again.

I would contact the landlord and ask them what his or her rules are. If you do not want to contact the landlord, you may want to contact the housing authority for your city/county that you reside and they will be able to provide you with accurate information which is more than likely is going to be a 15 to 30 advance notice. I hope this helps. Harrisburg, PA