If the papery husk has a green berry-like fruit (tomatillo = little tomato) inside it full of white seeds, you probably have a tomatillo.
The leaves can be smooth edged or serrate like these.
The flowers are downward facing and on pollination, develop the husk with the fruit growing inside.
The fruit (right) varies from green to black when ripe.
Once you have a good ident on it, you have a good source for green-sauce or green salsa. This is one fruit that you pick while green just before it completely fills the husk.
If you toss any of the fruit in your compost heap, I guarantee that you will have them everywhere, they are very hardy against even a hot heap.
Some compost added to the barrel to grow Bell Peppers had some hitchhikers. Hadn't the heart to pull them up, more green salsa and paella mix.