Is there an upper limit?

well,this is more of a short question,but I’m curious about something.

i have a ritual whereby I welcome a wandering spirit to my flesh,to share the body as it were. it doesn’t always stick,but it usually works. most spirits I find are content to sit in the background and experience my senses. but sometimes I find a thought or two leaking through the mostly artificial veil I’ve created that I can clearly tell isn’t mine. now you might ask “why oh my wouldn’t this be a problem?” . no it wouldn’t,I want more of it

in my eclectic its these extranatural thoughts which are often the foundation of much wisdom. yet I’m having trouble finding thoughtful spirits to “welcome home” as it were. I’m also worried if there is an upper limit seeing as every spirit welcomed has a theoretical right to thoughtform. how many mundane people can you stick in a room before it becomes white noise?etc.