In BASH, test if file exists does not work when filename in variable has single quotes

I'm trying to test if a file exists by passing the contents of a variable to the test -e of bash. The variable looks like this :

FILE1='/etc/wherever/whatever'

When i do :

[[ -e "$FILE1" ]]

$? equals to 1, and it says it can't find the file (above path is an example....)

Tried several options: double quotes around the filepath instead of single quotes (variable is obtained from a line in a file)

Found out it only works if I put the filepath in the file I read without any quotes. But that would be a problem when using filenames withe spaces in it.

So, to clarify: 1) file contains lines that are read one by one 2) columns in line are split using IFS into separate variables 3) one variable is a filename, that is enclosed in single quotes 4) a [[ -e $variable ]] can't find the file.

What would be the correct syntax, please ?