Short lived house guest

One night as I was getting ready for bed I looked up and ACK saw a lizard on my wall.  I of course called down and made Eric come look at it.  He informed me that it was a gecko and good to have in the house.  I then got out my ipad and looked up geckos and sure enough he matched the description of one.  Yes they are good to have in the house as they eat spiders, mosquitoes and other bugs but... if there is one gecko will there be more?  Will all of these geckos be shitting all over my walls?  Will my house smell like gecko shit, whatever that might smell like?

We were going to leave him alone until I voiced my concerns to my husband... he got thinking about all the gecko shit too.  Needless to say he was relocated outside :)