1) Be wary of companies that try and use take-home tests for free labor. According to Glassdoor reviews, ClipboardHealth is one that comes to mind that is allegedly notorious for this.

2) Asking for a "take-home" challenge before even having a 10-15 minute phone conversation and seeing if the position might be a mutual fit is incredibly disrespectful. I understand that getting a good job might involve jumping through some hoops, but asking for that as the initial contact in a recruitment process is incredibly scammy feeling and disrespectful.