OOK library

It is one of those 315/433MHz ASK/OOK receivers ?
When used with the Arduino on both ends, transmitter and receiver, the VirtualWire library is often used, VirtualWire: VirtualWire library for Arduino and other boards

For the most used protocol, the RCSwitch library is used, GitHub - sui77/rc-switch: Arduino lib to operate 433/315Mhz devices like power outlet sockets.

There are more libraries, I think one has 'fuzzy' in its name. There are also protocol analyzers, which can be used with a recorded reception.
Others have made libraries to capture data from weather stations and so.

What device do you want to receive ?