The Federal Trade Commission is asking Americans to be on the alert for fraudulent telemarketing medical-alert services.

According to the FTC, these companies place unsolicited phone calls to elderly people and try to pressure them into buying medical-alert services, such as a pendant that can summon emergency help by the push of a button.

Although people in some cases have refused to purchase the services, they have received letters in the mail demanding payment for unwanted services. The FTC says some people have received phony invoices and letters threatening legal action if people do not pay the bogus charges.

Anyone who has information about a medical-alert scheme or knows of a victim is asked to call the FTC at 202-326-2747.