Tried to follow the solution from can't install "CHAID" on Mac OS X 10.9.5 but it doesn't work for my case.
When I try to install the package from R-Forge and type as source, it shows following results:
install.packages("CHAID", repos="http://R-Forge.R-project.org", type = "source")
Installing package into ‘/Users/guilin/Library/R/3.2/library’(as ‘lib’ is unspecified)
Warning in install.packages :
package ‘CHAID’ is not available (for R version 3.2.2)
I also try to download it directly from R-forge website (CHAID_0.1-2.tar) and install it from local downloaded file, it also shows the same error.
package ‘~/Downloads/CHAID_0.1-2.tar’ is not available (for R version 3.2.2)