That's a pretty funny name. Where does searchgoose show up on your Firefox? For example:

Home Page

If searchgoose appears at startup or when you click the Home button or press Alt+Home, it may have taken over as your home page. Please see the steps in this article to regain control of that setting: How to set the home page.

Default Search Engine

When you type in the address bar, if it mentions searching with searchgoose instead of your preferred site, please see the steps in this article to regain control of that setting: Change your default search settings in Firefox.

Other Intrusions

If searchgoose shows up on your new tab page, or if you get a searchgood page at startup but it's not your home page, let us know more details and we can help diagnose the situation.

Also, more generally, I suggest doing a little malware scrubdown in case this unwanted software arrived as part of a bundle. This article suggests tools for that: Troubleshoot Firefox issues caused by malware.

Remove Searchgoose.com redirect (Virus Removal Guide) Web search: https://www.bing.com/search?q=searchgoose

You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed free to use malware scanners. Each works differently. If one program misses something, another may pick it up.